How does calcium absorption affect bone health. What factors influence calcium absorption in the body. Can calcium supplements help with various health conditions. Why is calcium crucial for overall wellbeing.

The Importance of Calcium in Human Health

Calcium, the most abundant mineral in the human body, plays a crucial role in maintaining overall health. About 99% of the body’s calcium is found in bones and teeth, where it contributes to their strength and structure. However, calcium’s importance extends far beyond skeletal health.

How does calcium impact various bodily functions? Calcium is essential for:

• Proper heart function
• Nerve signal transmission
• Muscle contraction
• Blood clotting
• Enzyme activation

Given its wide-ranging impact, maintaining adequate calcium levels is vital for overall wellbeing. However, the body’s ability to absorb and utilize calcium depends on various factors, which we’ll explore in detail.

Factors Influencing Calcium Absorption

Calcium absorption is a complex process influenced by numerous factors. Understanding these can help individuals optimize their calcium intake and utilization.

Nutrients That Enhance Calcium Absorption

Which nutrients work synergistically with calcium? Several nutrients play a crucial role in calcium absorption and utilization:

• Vitamin D: Often called the “sunshine vitamin,” it significantly enhances calcium absorption in the intestines.
• Vitamin K: This vitamin is essential for proper calcium utilization in bone formation.
• Magnesium: It works closely with calcium in bone metabolism and muscle function.
• Phosphorous: This mineral partners with calcium in building strong bones and teeth.

Factors That Hinder Calcium Absorption

What elements can impede calcium absorption? Several lifestyle factors and dietary components can reduce calcium absorption:

• Excessive caffeine intake
• Smoking
• High alcohol consumption
• Excessive soda consumption, especially those containing phosphoric acid
• High sodium intake, which increases calcium excretion

Interestingly, while some factors hinder absorption, others may enhance it. For instance, some studies suggest that certain carbohydrates might improve calcium absorption, although more research is needed to fully understand this relationship.

Age-Related Changes in Calcium Absorption

How does age affect calcium absorption? The body’s ability to absorb and retain calcium changes throughout life:

• Childhood and adolescence: Calcium absorption is at its peak, supporting rapid bone growth and development.
• Adulthood: Absorption rates begin to decline, but remain relatively stable.
• Post-30s: The body starts to lose more bone than it builds, increasing the importance of adequate calcium intake.
• Post-menopause: Women experience a sharp decline in calcium absorption due to hormonal changes.
• Older age: Both men and women experience reduced calcium absorption, increasing the risk of osteoporosis.

These age-related changes underscore the importance of lifelong calcium intake and highlight why certain age groups may require calcium supplements.

Health Conditions Affecting Calcium Absorption

Certain health conditions can significantly impact the body’s ability to absorb and utilize calcium effectively. Understanding these conditions is crucial for managing calcium levels and overall health.

Gastrointestinal Disorders

How do gastrointestinal conditions affect calcium absorption? Several digestive disorders can impair calcium absorption:

• Crohn’s disease: This inflammatory bowel disease can damage the intestinal lining, reducing calcium absorption.
• Celiac disease: Gluten intolerance can lead to intestinal damage, hindering nutrient absorption, including calcium.
• Intestinal surgeries: Procedures that remove portions of the small intestine can reduce the surface area available for calcium absorption.

Endocrine Disorders

What endocrine conditions impact calcium metabolism? Several hormonal imbalances can affect calcium levels:

• Hypoparathyroidism: Underactive parathyroid glands lead to inadequate production of parathyroid hormone, which regulates calcium levels.
• Vitamin D deficiency: As vitamin D is crucial for calcium absorption, its deficiency can significantly impact calcium levels.
• Thyroid disorders: Both hypothyroidism and hyperthyroidism can affect calcium metabolism.

Individuals with these conditions often require careful monitoring of their calcium levels and may need supplementation under medical supervision.

Calcium Supplementation: Benefits and Considerations

While obtaining calcium through diet is ideal, some individuals may require calcium supplements to meet their needs. However, supplementation should be approached thoughtfully and under medical guidance.

Potential Benefits of Calcium Supplements

In what situations might calcium supplements be beneficial? Calcium supplementation may be recommended for:

• Preventing or treating osteoporosis
• Managing hypoparathyroidism
• Alleviating symptoms of premenstrual syndrome (PMS)
• Potentially aiding in blood pressure management
• Possible role in weight management (though more research is needed)

Considerations and Potential Risks

What factors should be considered before starting calcium supplements? Several aspects warrant attention:

• Dosage: Excessive calcium intake can lead to hypercalcemia and other health issues.
• Timing: Calcium absorption is most efficient when taken in smaller doses throughout the day.
• Interaction with medications: Calcium can interfere with the absorption of certain drugs, including antibiotics and thyroid medications.
• Form of calcium: Different forms (e.g., calcium carbonate, calcium citrate) have varying absorption rates and may be better suited for different individuals.
• Balancing with other nutrients: Ensure adequate intake of vitamin D and other co-factors for optimal absorption.

It’s crucial to consult with a healthcare provider before starting any supplementation regimen to ensure it’s appropriate for your individual needs and health status.

Dietary Sources of Calcium

While supplements can be beneficial in certain situations, obtaining calcium through diet remains the preferred method for most individuals. A diverse range of foods can contribute to meeting daily calcium requirements.

Dairy Products

Which dairy products are rich in calcium? Dairy is often considered the most readily available source of calcium:

• Milk: One cup of cow’s milk provides about 300 mg of calcium.
• Yogurt: A 6-ounce serving can contain 200-300 mg of calcium.
• Cheese: Calcium content varies, but hard cheeses like parmesan are particularly rich sources.

Non-Dairy Sources

What options are available for those who don’t consume dairy? Numerous non-dairy foods are excellent calcium sources:

• Leafy greens: Kale, collard greens, and spinach are calcium-rich vegetables.
• Fish with edible bones: Sardines and canned salmon provide both calcium and omega-3 fatty acids.
• Fortified foods: Many plant-based milk alternatives, cereals, and juices are fortified with calcium.
• Nuts and seeds: Almonds and sesame seeds contain significant amounts of calcium.
• Legumes: Soybeans and white beans are good plant-based calcium sources.

By incorporating a variety of these foods into one’s diet, it’s possible to meet calcium needs without relying on supplements.

Calcium’s Role in Specific Health Conditions

Beyond its well-known benefits for bone health, calcium plays a role in various other health conditions. Understanding these connections can provide insights into the far-reaching impact of this essential mineral.

Cardiovascular Health

How does calcium affect heart health? The relationship between calcium and cardiovascular health is complex:

• Blood pressure: Some studies suggest that adequate calcium intake may help lower blood pressure, particularly in pregnancy.
• Heart rhythm: Calcium is crucial for proper heart muscle contraction and maintaining a regular heartbeat.
• Cholesterol: Preliminary research indicates that calcium might play a role in maintaining healthy cholesterol levels, though more studies are needed.

Women’s Health

What specific benefits does calcium offer for women’s health?

• Premenstrual Syndrome (PMS): Research has shown that calcium supplementation can significantly reduce PMS symptoms, including mood swings, bloating, and cramps.
• Pregnancy: Adequate calcium intake during pregnancy is crucial for fetal bone development and may reduce the risk of preeclampsia.
• Menopause: Calcium, especially when combined with vitamin D, can help mitigate bone loss associated with menopause.

Metabolic Health

How might calcium influence metabolic processes? Emerging research suggests potential connections between calcium and metabolic health:

• Weight management: Some studies indicate that calcium from dairy sources might aid in weight loss or maintenance, though the exact mechanism is not fully understood.
• Insulin sensitivity: Preliminary research suggests a potential link between calcium intake and improved insulin sensitivity, though more studies are needed to confirm this relationship.

While these potential benefits are intriguing, it’s important to note that calcium is not a panacea. Its effects often depend on overall diet, lifestyle, and individual health status.

Calcium Deficiency: Risks and Symptoms

Despite calcium’s abundance in many foods, deficiency can occur, particularly in certain populations or due to specific health conditions. Recognizing the signs of calcium deficiency is crucial for timely intervention.

Populations at Risk

Who is most susceptible to calcium deficiency? Several groups are at higher risk:

• Postmenopausal women: Due to decreased estrogen levels, which aid in calcium absorption
• Individuals with lactose intolerance or dairy allergies: If adequate alternative sources are not consumed
• People with certain gastrointestinal disorders: Conditions like Crohn’s disease or celiac disease can impair absorption
• Vegans and some vegetarians: If diet is not carefully planned to include non-dairy calcium sources
• Individuals taking certain medications: Some drugs can interfere with calcium absorption or increase excretion

Symptoms of Calcium Deficiency

What are the signs of insufficient calcium levels? Symptoms can range from mild to severe:

• Muscle cramps and spasms
• Numbness and tingling in the fingers
• Fatigue and weakness
• Dry, itchy skin
• Brittle nails
• Depression
• In severe cases, seizures and abnormal heart rhythms

It’s important to note that many of these symptoms can be associated with other conditions. If you suspect calcium deficiency, consult a healthcare provider for proper diagnosis and treatment.

Future Directions in Calcium Research

As our understanding of calcium’s role in human health continues to evolve, several areas of research are emerging as particularly promising for future investigations.

Calcium and Gut Health

How might calcium influence the gut microbiome? Recent studies have begun to explore the relationship between calcium intake and gut health:

• Prebiotic effects: Some research suggests that calcium might act as a prebiotic, promoting the growth of beneficial gut bacteria.
• Gut barrier function: Calcium may play a role in maintaining the integrity of the intestinal lining, potentially influencing nutrient absorption and immune function.
• Interaction with probiotics: The interplay between calcium and probiotic supplements is an area of ongoing research, with potential implications for digestive health.

Calcium and Cognitive Function

Could calcium play a role in brain health? Emerging research is exploring potential connections:

• Neurotransmitter release: Calcium is crucial for the release of neurotransmitters, which are essential for cognitive function.
• Neuroprotection: Some studies suggest that adequate calcium intake might have neuroprotective effects, potentially influencing age-related cognitive decline.
• Mood regulation: Given calcium’s role in neurotransmitter function, researchers are investigating its potential impact on mood disorders.

Personalized Calcium Recommendations

How might future research refine calcium intake guidelines? As we move towards more personalized nutrition, several factors are being considered:

• Genetic variations: Research into how genetic differences affect calcium metabolism could lead to more tailored recommendations.
• Life stage-specific needs: Further studies may help fine-tune calcium requirements for different life stages, from childhood through older adulthood.
• Interaction with other nutrients: Ongoing research aims to better understand how calcium interacts with other nutrients, potentially leading to more comprehensive dietary guidelines.

These areas of research hold promise for enhancing our understanding of calcium’s multifaceted role in human health and may lead to more nuanced and personalized approaches to calcium intake and supplementation in the future.

Calcium Information | Mount Sinai

Calcium is the most abundant mineral in your body. It is essential for the development and maintenance of strong bones and teeth, where about 99% of the body’s calcium is found. Calcium also helps the heart, nerves, muscles, and other body systems work properly. It is probably best known for helping prevent osteoporosis.

Your body needs several other nutrients in order for calcium to be absorbed and used properly, including magnesium, phosphorous, and especially vitamins D and K. Many factors, including age, disease states, and medications, can affect calcium absorption. Carbohydrates may enhance calcium absorption while coffee and cigarette smoke may impede it.

The best way to get calcium is through food. Many foods are fortified with calcium. But some people may need to take calcium supplements to get the recommended amount. It is especially important for children to get enough calcium in their diets as they are growing and forming bone, and for older people as they start to lose bone.

Postmenopausal women, people who consume large amounts of caffeine, alcohol, or soda, and those who take corticosteroid medications may need calcium supplements. Calcium deficiency can be found in people who don’t absorb enough calcium, as can happen with Crohn’s disease, celiac disease, and some intestinal surgeries.

Getting enough calcium may help prevent or treat the following conditions:

Osteoporosis

Your body needs calcium to build and maintain healthy bones and strong teeth. People start to lose more bone than their bodies make in their 30s, and the process speeds up as they get older. Studies have shown that calcium, particularly in combination with vitamin D, may help prevent bone loss associated with menopause. It may also help prevent bone loss in older men. If you do not get enough calcium in your diet, your doctor may recommend a supplement.

Hypoparathyroidism

People with this condition have underactive parathyroid glands. These four small glands sit on the four corners of the thyroid in the neck and produce a hormone that regulates calcium, phosphorous, and vitamin D levels in the body. People with this condition should follow a high-calcium, low-phosphorous diet as prescribed by their doctors. Often, they will also need to take calcium supplements.

Premenstrual Syndrome (PMS)

One large, well-designed study showed that women who took 1,200 mg of calcium per day reduced their symptoms of PMS by 50%, including headache, moodiness, food cravings, and bloating. A smaller study suggested that calcium may help reduce menstrual pain.

High Blood Pressure

People who do not get enough calcium may be at higher risk for hypertension or high blood pressure. Some studies suggest that increasing calcium levels may lower blood pressure slightly. However, not all studies have been positive. Researchers aren’t sure whether calcium supplements would have any benefit, or whether it’s the effects of a diet that includes low-fat dairy products (which contain calcium) that is responsible.

If you want to try calcium supplements, do not stop taking your blood pressure medication. Instead, talk to your doctor about the right amount of calcium for you. You may need to take calcium for 6 to 8 weeks before you see any improvement in blood pressure.

Some studies suggest that calcium supplements may play a role in the prevention of high blood pressure during pregnancy and preeclampsia, a combination of high blood pressure, fluid retention, and high levels of protein in the urine that some women develop during the last trimester of pregnancy. However, not all studies show the same benefit. Taking a prenatal vitamin, with magnesium, folic acid, and many other nutrients, and getting enough calcium in food, may lower the risk of developing high blood pressure during pregnancy.

Obesity and Weight Loss

Animal and human studies have found that eating low-fat dairy products may help you lose weight or stay at a healthy weight. However, researchers aren’t sure whether the calcium in the dairy products affects weight, or whether it’s some other nutrient — or even a combination of nutrients. In addition, not all studies have been positive. Plus there’s no sound evidence that taking calcium supplements, as opposed to eating low-fat dairy products, would help with weight loss. More research is needed.

High Cholesterol

Preliminary studies in animals and people suggest that calcium supplements, in the range of 1,500 to 2,000 mg per day, may help lower cholesterol slightly. From these studies, it seems that calcium supplements, along with exercise and a healthy diet, may be better at keeping cholesterol at normal levels than at lowering already high cholesterol. More research is needed.

Rickets

Rickets causes softening and weakening of the bone in children. Although very rare in North America and Western Europe, where children drink a lot of milk, it still happens in many parts of the world. Researchers thought rickets was caused by a vitamin D deficiency. But studies suggest that taking calcium supplements is an effective treatment.

Other Uses

Stroke. In a population-based study, in which large groups of people were followed over time, women who took in more calcium, both through food and supplements, were less likely to have a stroke over a 14-year period. More research is needed.

Colon Cancer. Although not all studies agree, some show that people who have higher amounts of calcium, vitamin D, and milk in their diets are less likely to develop colorectal cancer than those who have low amounts. Researchers are not sure whether calcium supplements would have the same effect, or even whether calcium itself is making the difference.

Dietary Sources

The richest food sources of calcium include:

• Cheeses, such as Parmesan, Romano, gruyere, cheddar, American, mozzarella, and feta
• Low-fat dairy products, such as milk and yogurt
• Tofu
• Blackstrap molasses

Other good sources of calcium include:

• Almonds
• Brewer’s yeast
• Bok choy
• Brazil nuts
• Broccoli
• Cabbage
• Dried figs
• Kelp
• Dark leafy greens (such as dandelion, turnip, collard, mustard, kale, and Swiss chard)
• Hazelnuts
• Oysters
• Sardines
• Canned salmon

Foods that are fortified with calcium — such as juices, soy milk, rice milk, tofu and cereals — are also good sources of this mineral.

Available Forms

There are many forms of calcium available as dietary supplements. They differ in the amount of calcium they contain, how well the body absorbs them, and how much they cost. The two most popular forms are calcium citrate and calcium carbonate.

• Calcium citrate. Easily absorbed and digested by the body. It does not contain as much elemental calcium — the amount your body actually absorbs — as calcium carbonate. It is more expensive than calcium carbonate. Also, calcium citrate should not be used with aluminum-containing antacids.
• Calcium carbonate. Less expensive than calcium citrate and contains more elemental calcium. Requires a certain amount of stomach acid to be absorbed. So it is usually taken with a glass of orange juice. Many antacids contain calcium carbonate.

Avoid calcium supplements that are derived from oyster shells, dolomite, and bone meal as they may contain lead, a toxic metal that can harm the brain and kidneys, cause anemia, and raise blood pressure.

How to Take It

Calcium supplements should be taken in small doses (no more than 500 mg at a time) during the day with 6 to 8 cups of water to avoid constipation.

The following are daily dietary recommendations from the Institute of Medicine.

Pediatric

Talk to your pediatrician before giving a child any nutritional supplement, including calcium.

• Birth to 6 months: 200 mg
• 7 months to 1 year: 260 mg
• 1 to 3 years: 700 mg
• 4 to 8 years: 1000 mg
• 9 to 18 years: 1,300 mg

Adult

• 19 to 50 years: 1,000 mg
• Women 51 years and older: 1,200 mg
• Men 51 to 70 years: 1,000 mg
• Men older than 70: 1,200 mg
• Pregnant and breastfeeding women under 19 years: 1,300 mg
• Pregnant and breastfeeding women 19 years and older: 1,000 mg

For prevention of colon cancer, some researchers recommend 1,800 mg per day. Speak with your doctor to determine the right dose for you.

Precautions

Take dietary supplements only under the supervision of a knowledgeable health care provider since there is a potential for side effects. Total calcium intake, from combined dietary and supplemental sources, should not exceed 2,500 mg per day.

Side effects can include constipation and stomach upset. Very high doses can cause:

• Nausea and vomiting
• Loss of appetite
• Increased urination
• Kidney damage
• Confusion
• Irregular heart rhythm

People with hyperparathyroidism, kidney failure, sarcoidosis, or cancer could be at risk for high levels of calcium and should not take calcium supplements.

People with a history of kidney stones should not take calcium supplements. However, some research suggests that calcium in foods may not increase the risk of kidney stones. If you have or have had kidney stones, talk to your doctor about whether you should limit calcium in your diet.

Some population studies suggest that getting high amounts (more than 2,000 mg per day) of calcium through the diet may increase the risk of prostate cancer. Two of these studies found that low-fat and nonfat milk — but not other dairy foods — was associated with a higher risk of advanced prostate cancer. But these studies don’t prove that drinking low-fat or nonfat milk causes an increased risk of prostate cancer. And some research suggests that the amount of calcium in the diet isn’t associated with prostate cancer risk. If you have prostate cancer, or are concerned about dairy products and prostate cancer risk, talk to your doctor.

The Institute of Medicine sets the tolerable upper level of daily calcium intake at 2,500 mg. Some studies have suggested that getting amounts higher than 1,000 to 1,200 mg/day may be associated with an increased risk of heart attack. More research is needed.

When figuring out how much calcium you need, be sure to take into account the calcium-rich foods you eat — such as cheese, yogurt, milk — along with any supplements.

Possible Interactions

If you are being treated with any of the following medications, you should not use calcium supplements without talking to your doctor first.

Ceftriaxone (Rocephin)

These medications may have potentially fatal interactions with calcium.

Biphosphates

These medications are used to treat osteoporosis and some other bone conditions. Calcium may interfere with how your body absorbs them. Calcium-containing products should be taken at least 2 hours before or after bisphosphonates. Bisphosphonates include:

• Alendronate (Fosamax)
• Etidronate (Didronel)
• Ibandronate (Boniva)
• Risedronate (Actonel)
• Tiludronate (Skelid)
• Zoledronic acid (Reclast)

Antacids that contain aluminum

When calcium citrate is taken with these antacids, the amount of aluminum absorbed into the blood may go up. For people with kidney disease, the aluminum levels could be toxic.

Blood pressure medications

Taking calcium with a beta-blocker may interfere with blood levels of both the calcium and the beta-blocker. Study results aren’t clear, however. It also has been reported that calcium interferes with calcium channel blockers. But these study results are also mixed. If you take a beta-blocker or calcium-channel blocker, do not take calcium supplements without your doctor’s supervision. Beta-blockers include atenolol (Tenormin), metoprolol (Lopressor, Toprol-XL), and propranolol (Inderal, Inderal LA), among others. Calcium-channel blockers include amlodipine (Norvasc), diltiazem (Cardizem), and nifedipine (Procardia).

Cholesterol-lowering medications

A type of medication known as bile acid sequestrants, used to treat high cholesterol, may interfere with calcium absorption and raise the amount of calcium that leaves the body in urine. Your doctor may recommend taking calcium and vitamin D supplements. These drugs include cholestyramine (Questran), colestipol (Colestid), colesevelam (Welchol).

Calcipotriene (Dovenex)

Taking calcium supplements while using calcipotriene, a topical medication for psoriasis, could increase the risk of having calcium levels that are too high (hypercalcemia).

Corticosteroids (prednisone)

If you take corticosteroids on a long-term basis, you may need to take calcium supplements.

Digoxin

High levels of calcium may raise the risk of a toxic reaction to digoxin, a medication used to treat irregular heart rhythms. On the other hand, low levels of calcium keep digoxin from working. If you take digoxin, your doctor should monitor your calcium levels closely.

Diuretics (water pills)

Different types of diuretics interact with calcium in opposite ways:

• Thiazide diuretics can raise calcium levels in the blood. These drugs include chlorothiazide (Diuril), hydrochlorothiazide, ghlorthalidone (Hygroton), indapamide (Lozol), metolozone (Zaroxolyn), and polythiazide (Renese), among others.
• Loop diuretics can decrease calcium levels. These drugs include furosemide (Lasix) and bumetanide (Bumex).
• Amiloride (Midamor) is a type of diuretic called a potassium-sparing diuretic. It may reduce the amount of calcium your body eliminates in urine, and raise calcium levels in the blood, especially in people with kidney stones.

Estrogens

Estrogens may contribute to an overall increase in calcium blood levels. Taking calcium supplements with estrogens improves bone density.

Gentamicin

Taking calcium during treatment with the antibiotic gentamicin may increase the potential for toxic effects on the kidneys.

Sotalol (Betapace)

Sotalol is used to treat an irregular heartbeat. Calcium may decrease how much sotalol is absorbed by the body.

Thyroid hormone

Calcium can decrease the amount of thyroid hormone medication that your body absorbs.

Antibiotics

Different types of antibiotics interact with calcium:

• Quinolones. Calcium can interfere with the body’s ability to absorb quinolone antibiotics. These drugs include ciprofloxacin (Cipro), levofloxacin (Levaquin), norfloxacin (Noroxin), and ofloxacin (Floxin). Take calcium supplements 2 to 4 hours before or after taking quinolone antibiotics.
• Tetracyclines. Calcium can interfere with the body’s ability to absorb tetracycline antibiotics, including doxycycline, minocycline, and tetracycline. Take calcium supplements 2 to 4 hours before or after taking tetracycline antibiotics.

Anti seizure medications

Some seizure medications, such as phenytoin (Dilantin), carbamazepine (Tegretol), phenobarbitol, and primidone (Mysoline), may lower levels of calcium in the body. Some doctors recommend taking vitamin D along with anti seizure drugs to keep calcium levels up. Take doses of calcium and anti seizure medications at least 2 hours apart because each interferes with the absorption of the other.

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Did you know that certain foods block calcium absorption?

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You try to eat a healthy, calcium-rich diet. You watch your weight. You exercise. You do everything in your power to maintain strong bones because you want to be active well into your 70s and 80s.

You even make sure you have a nutritious breakfast of natural whole wheat squares topped cold, vitamin-D-fortified milk.

It sounds like a nutritious way to your day. But eating whole-wheat cereal and milk together may not be the best menu choice if you are trying to increase your bone mass. There are certain foods, like wheat, that block calcium absorption.

Phytates bind calcium.

High-fiber foods contain phytates, which prevent the body from absorbing calcium in other foods. Eating a high-fiber, whole-wheat cereal with milk, macaroni and cheese, or drinking a tall, cold glass of milk with Boston baked beans and hot dogs may be great-tasting combinations, but they do not boost bone-building nutrition.

Phytates found in whole-grains, legumes (dried beans), nuts and soy products bind the calcium of other foods eaten when they are eaten at the same time. When calcium is bound, the body cannot use it.

Oxalic acid hinders calcium absorption.

Foods high in oxalic acid also impede the absorption of calcium by binding the mineral.

Spinach is naturally high in calcium, but it is also high in oxalic acid. The body is unable to process the calcium it provides. Other foods that contain oxalic acid include beet greens, rhubarb and sweet potatoes.

Though these foods should not be considered for their calcium value, they do provide other nutrients and minerals that help the body stay healthy.

Does protein interfere with calcium absorption?

Historically, nutritionists have warned that eating large amounts of protein causes the kidneys to flush calcium out of the body. But recent studies show protein also may increase intestinal calcium absorption.

More study is needed to determine protein’s effect on the body’s ability to process calcium. To make the most of your calcium intake, don’t drink milk with your beef stew, chili or steak dinner. Eat your meal and then drink your milk later.

Beer, cheese and snacks are a trifecta for calcium loss.

Alcohol and salty foods are catalysts for calcium flushing. As calcium levels in the blood decrease, the body extracts (resorbing) calcium from the bones to obtain the calcium it needs to function properly. Calcium flushing can make the bones porous, which can lead to the development of osteoporosis.

To minimize calcium flushing:

• Avoid eating foods that have a sodium content higher than 20 percent of the daily recommended value.
• Don’t drink more than two or three alcoholic drinks a day.

You can eat your spinach and build your calcium, too.

Wheat and other “bad-to-the-bone” foods provide many other vitamins and minerals vital to your health. You should still eat these types of foods, just not at the same time that you drink milk or eat calcium-rich foods.

The best way to maximize the nutrition from foods that bind or flush calcium and continue to boost your calcium levels is just a matter of scheduling. Eat calcium-binding foods at least two hours before or after you eat calcium-rich foods. This timing allows your body to maximize the vitamins and minerals of all food types. By making this timely adjustment to your meals, you gain all the nutritional benefits without interfering with your body’s ability to absorb the calcium it needs every day.

Source:
The National Institutes of Health Office of Dietary Supplements

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Calcium in daily urine

General information about the study

Every day we lose part of the calcium after it is filtered by the kidneys and excreted in the urine. This analysis allows you to determine such daily loss of calcium through the kidneys.

Calcium is a cation that is absorbed into the general circulation from food. It is involved in bone formation, nerve impulse transmission, muscle contraction and blood clotting. Calcium is found in the bones, circulates in the blood, is filtered by the kidneys, and is mostly reabsorbed at normal levels in the blood. With an increase in the concentration of serum calcium, the kidneys slow down the processes of reverse reabsorption, due to this, the level of calcium in the urine increases.

The balance of calcium excretion and absorption is closely related to phosphate (phosphates are salts of phosphoric acid). With an increase in the concentration of calcium in the blood, the level of phosphate decreases, when the content of phosphate increases, the proportion of calcium decreases.

Mechanisms of phosphorus-calcium metabolism:

• parathyroid glands at high phosphate levels (at low calcium levels) secrete parathormone, which stimulates osteoclasts, which destroy bone tissue, thereby increasing the concentration of calcium in the blood;
• When calcium levels in the blood are high, the thyroid gland secretes calcitonin, which causes calcium to move from the blood to the bones;
• The parathyroid glands also activate vitamin D, increasing calcium absorption in the gastrointestinal tract and cation reabsorption in the kidneys.

Urinary calcium is needed to assess calcium intake and/or the balance between calcium absorption, bone resorption and calcium excretion through the kidneys.

What is research used for?

• To determine the amount of calcium consumed and its absorption in the intestine.
• To find the cause of bone calcium loss (osteoporosis).
• For the diagnosis of kidney disease.
• To assess the functions of the parathyroid glands.

When is the test ordered?

• Calcium in the urine, unlike all other indicators of the composition of urine, is rarely studied.
• In the diagnosis of diseases of the parathyroid glands and familial hypocalciuric hypercalcemia (insufficient excretion of calcium in the urine due to a violation of the intrarenal mechanism).
• With symptoms of urolithiasis: sharp and acute pain in the right or left lumbar region, the spread of this pain below and somewhat to the lateral areas of the abdomen, impaired urination, and the appearance of blood in the urine (this symptom alone is enough).
• In the diagnosis of digestive disorders that may affect the small intestine, where the absorption of essential nutrients occurs (together with other tests).

Description of article

General information about the study
What is research used for?
When is the study scheduled?

Calcium. General information

In the human body, more than 98% of Ca is fixed in bone tissue, and only 1–2% is in soft tissues and extracellular fluid, incl. in blood. In the blood serum, 40% Ca circulates in complex with proteins, 9% in the form of salts (phosphates, citrate), the remaining 50% are present in the ionized (free) form (Ca2+) and therefore are able to diffuse into the intercellular fluid. It is free calcium that is the regulator of intracellular processes.

Physiologically, the action of Ca is associated with the regulation of the permeability of cell membranes. In the cell, its concentration is very low; on the outer side of the plasma membrane, the Ca2+ content is many times higher. The establishment of such a balance of concentrations is ensured by the energy-dependent operation of membrane channels and pumps. Due to the low content of Ca2+ in the cytoplasm and the high concentration gradient on both sides of the plasma membrane, this ion is important in the regulation of cell activity. The plasma membrane of cells has a low permeability to calcium; the removal of the ion from the cell is energy dependent. Changes in the conductivity of calcium channels in the membrane and intracellular Ca2+ content change the functioning of many systems, including the processes of cell division. Calcium ions play an important role in the transmission of nerve impulses, muscle contractility, in the process of blood coagulation, and are cofactors in a number of enzymatic reactions. Determining the level of calcium is a diagnostically and prognostically significant test for a number of pathological conditions.

To maintain a normal level of calcium in the blood serum, it is necessary to adequately supply it with food. The intake of calcium in the body is affected by its content in food and their composition. The presence in the diet of substances that bind calcium, primarily phosphates and fatty acids, significantly reduces its absorption. Calcium absorption occurs predominantly in the proximal small intestine and in the jejunum. The intestines absorb from 30 to 70% of the calcium supplied with food.

Clinically, hypercalcemia manifests itself as a violation of the kidneys (polyuria, urolithiasis), gastrointestinal tract (nausea, vomiting, constipation), heart (shortening of the QT interval on the ECG), neurological symptoms (weakness, fatigue, confusion, stupor and coma). Clinical manifestations of hypercalcemia are more pronounced with its rapid development.

Clinical manifestations of hypocalcemia vary depending on the degree of calcium reduction. Muscle fatigue, weakness, twitching of individual muscle groups, positive symptoms of Khvostek, Trousseau, Lust are noted with a mild degree of hypocalcemia. Alkalosis increases the albumin-bound calcium fraction, exacerbating symptoms. Severe hypocalcemia causes drowsiness, confusion, spasms of smooth muscles, hypertonicity and convulsions, prolongation of the QT interval on the ECG. Chronic hypocalcemia can cause cataracts and calcification of the basal ganglia.

The exchange of calcium in the body is closely related to the exchange of phosphorus. The main factors regulating the metabolism of phosphates and calcium include PTH, calcitonin and vitamin D. When hypocalcemia occurs, an increase in PTH synthesis occurs, which provides increased tubular reabsorption and a decrease in calcium excretion in the urine. At the same time, under the influence of PTH, the excretion of phosphorus by the kidneys increases, which leads to a decrease in the concentration of phosphorus in the blood serum and extracellular fluid and a subsequent increase in the level of calcium in the blood. Hyperphosphatemia is accompanied by a decrease in calcium concentration, which leads to stimulation of the release of PTH, a decrease in tubular reabsorption of phosphate and an increase in its excretion by the kidneys.