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Calcium helps absorb vitamin d: Calcium and Vitamin D: Skeletal and Extraskeletal Health

Calcium and Vitamin D: Skeletal and Extraskeletal Health

Papers of particular interest, published recently, have been highlighted as:

• Of importance

•• Of major importance

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[Of importanceA prospective cohort study of the Nurses’ Health Study and Nurses’ Health Study II cohorts. After 22 years of follow-up, of 186,389 women, investigators found 190 new cases of confirmed SLE and 722 new cases of RA. No association was found between vitamin D intake (based on food frequency questionnaire) and incidence of SLE or RA.] [PMC free article] [PubMed] [Google Scholar]

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Calcium/Vitamin D Requirements, Recommended Foods & Supplements

Calcium and vitamin D are essential to building strong, dense bones both when you’re young and as you age. The information included here will help you learn all about calcium and vitamin D – the two most important nutrients for bone health.

It is equally important to continue getting enough calcium and vitamin D to prevent further bone loss if you are prescribed a medication to prevent bone loss or fractures.

What is Calcium and What Does it Do?

A calcium-rich diet (including dairy, nuts, leafy greens and fish) helps to build and protect your bones.

Calcium is a mineral that is necessary for life. In addition to building bones and keeping them healthy, calcium enables our blood to clot, our muscles to contract, and our heart to beat. About 99% of the calcium in our bodies is in our bones and teeth.

Every day, we lose calcium through our skin, nails, hair, sweat, urine and feces. Our bodies cannot produce its own calcium. That’s why it’s important to get enough calcium from the food we eat. When we don’t get the calcium our body needs, it is taken from our bones. This imbalance causes bones get weak and easier to break.

Too many Americans fall short of getting the amount of calcium they need every day and that can lead to bone loss, low bone density and even broken bones.

How Much Calcium Do You Need?

The amount of calcium you need every day depends on your age and sex.

Age 50 & younger1,000 mg* daily
Age 51 & older1,200 mg* daily

Age 70 & younger1,000 mg* daily
Age 71 & older1,200 mg* daily

*This includes the total amount of calcium you get from food and supplements.


How Much Calcium Do You Eat?

Use the International Osteoporosis Foundation’s Calcium Calculator to find out.

Sources of Calcium

Calcium-Rich Food Sources

Food is the best source of calcium. Dairy products, such as milk, yogurt, and cheese are high in calcium. Certain green vegetables and other foods contain calcium in smaller amounts. Some juices, breakfast foods, soymilk, cereals, snacks, breads and bottled water have added calcium in fortified foods. If you consume soymilk, other nut based milks ( i.e.: almond or oat milk) or another liquid that is fortified with calcium, be sure to shake the container well as calcium can settle to the bottom.

A simple way to add calcium to many foods is to add a single tablespoon of nonfat powdered milk, which contains about 50 mg of calcium. It is easy to add a few tablespoons to almost any recipe.

Reading Food Labels – How Much Calcium Am I Getting?

To determine how much calcium is in a particular food, check the nutrition facts panel for the daily value (DV). Food labels list calcium as a percentage of the DV. This amount is based on 1,000 mg of calcium per day. For example:

  • 30% DV of calcium equals 300 mg of calcium.
  • 20% DV of calcium equals 200 mg of calcium.
  • 15% DV of calcium equals 150 mg of calcium.

Calcium Supplements

The amount of calcium you need from a supplement depends on how much you get from food. Try to get the daily amount recommended from food and only supplement as needed to achieve the recommend daily allowance. In general, you shouldn’t take excess supplements that you don’t need. If you get enough calcium from foods, you may not need to take a supplement. There is no added benefit to taking more calcium than you need. Doing so may even carry some risks such as constipation, kidney stones and perhaps excess heart calcification.

Calcium supplements are available without a prescription in a wide range of preparations (including chewable tablets, gummy preparations, powders and liquid) and in varying amounts and sizes. The best supplement is the one that meets your needs for tolerability, convenience, cost, and availability. When choosing a supplement, keep the following in mind:

  • Choose brand-name supplements with proven reliability. Look for labels that state “purified” or have the USP (United States Pharmacopeia) symbol. The “USP Verified Mark” on the supplement label means that the USP has tested and found the calcium supplement to meet its standards for purity and quality.
  • Read the product label carefully to determine the amount of elemental calcium, which is the actual amount of calcium in the supplement, as well as how many doses or pills you have to take. When reading the label, pay close attention to the “amount per serving” and “serving size.”
  • Calcium is absorbed best when taken in amounts of 500 – 600 mg or less. This is the case for both foods and supplements. Try to get your calcium-rich foods and/or supplements in small amounts throughout the day, preferably with a meal. While it’s not recommended, taking your calcium all at once is better than not taking it at all.
  • Take (most) calcium supplements with food. Eating food produces stomach acid that helps your body absorb most calcium supplements. The one exception to the rule is calcium citrate, which can absorb well when taken with or without food.
  • When starting a new calcium supplement, start with a smaller amount to better tolerate it. When switching supplements, try starting with 200-300 mg every day for a week, and drink an extra 6-8 ounces of water with it. Then gradually add more calcium each week.
  • Side effects from calcium supplements, such as gas or constipation may occur or worsen. If increasing fluids in your diet and obtaining enough fiber does not solve the problem, try another type or brand of calcium. It may require trial and error to find the right supplement for you, but fortunately there are many choices.
  • Talk with your healthcare provider or pharmacist about possible interactions between prescription or over-the-counter medications and calcium supplements.

What is Vitamin D and What Does it Do?

Vitamin D is a fat soluble vitamin and plays an important role in protecting your bones, both by helping your body absorb calcium and by supporting muscles needed to avoid falls. Children need vitamin D to build strong bones, and adults need it to keep their bones strong and healthy.

How Much Vitamin D Do You Need?

Women and Men
Under age 50400-800 international units (IU) daily**
Age 50 and older800-1,000 IU daily**

**According to the National Academy of Medicine and National Institutes of Health the safe upper limit of vitamin D is 4,000 IU per day for most adults. These recommendations are for the general healthy adult population.


Sources of Vitamin D

There are three ways to get vitamin D:

  • Sunlight
  • Food
  • Supplements


Your skin makes vitamin D in reaction to sunlight and stores it in fat for later use. How much vitamin D your skin can produce depends on time of day, season, latitude, skin pigmentation, age, and other factors.

There are many reasons people do not have enough vitamin D. As we age, our skin loses its ability to generate vitamin D. People who live in cities or in institutional settings like nursing homes spend too little time outdoors. Even people who spend time outdoors often use sunscreen to prevent skin cancer. Sunscreen with an SPF as low as 8 reduces vitamin D production by 95 percent.

Vitamin D in Food

Vitamin D is found in very few foods. Sources include fatty fish like wild-caught mackerel, salmon, and tuna. Vitamin D is added to milk and other dairy products, orange juice, soymilk, and fortified cereals.

Check the food label to see if vitamin D has been added to a particular product. One eight-ounce serving of milk usually has 25% of the daily value (DV) of vitamin D. The DV is based on a total daily intake of 400 IU of vitamin D. So, a serving of milk with 25% of the DV of vitamin D contains 100 IU.

It is often difficult to get all the vitamin D you need from sunlight and food alone. Some people with underlying conditions may need to take vitamin D supplements to support bone health.

Vitamin D Supplements

Healthy adults with no vitamin D deficiency should be able to get adequate amounts of vitamin D from sunlight and by consuming a well-balanced diet. People with osteoporosis and low bone mass should discuss their vitamin D levels with their healthcare provider to ensure they are getting an optimal amount.

Before adding a vitamin D supplement, check to see if any of the other supplements, multivitamins, or medications you take contain vitamin D. Many calcium supplements also contain some vitamin D.

There are two types of vitamin D supplements. They are vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol). Both types are good for bone health.

Vitamin D supplements can be taken with or without food and the full amount can be taken at one time. While your body needs vitamin D to absorb calcium, you do not need to take vitamin D at the same time as a calcium supplement. If you need help choosing a vitamin D supplement, ask your healthcare provider to recommend one.

Vitamin D Deficiency: Are You at Risk?

Vitamin D deficiency occurs when you are not getting the recommended level of vitamin D over time. Certain people are at higher risk for vitamin D deficiency, including:

  • People who spend little time in the sun or those who regularly cover up when outdoors;
  • People living in nursing homes or other institutions or who are homebound;
  • People with certain medical conditions such as Celiac disease and inflammatory bowel disease;
  • People taking medicines that affect vitamin D levels such as certain anti-seizure medicines;
  • People with very dark skin;
  • Obese or very overweight people; and
  • Older adults with certain risk factors.

Talk to your healthcare provider if you have any of these risk factors. If you have osteoporosis, low bone mass or another medical condition that can lead to bone loss and also have a vitamin D deficiency, your healthcare provider may recommend vitamin D supplement to bring you up to a healthy 25-hydroxy vitamin D level which is generally agreed upon by medical societies to be between 30-60 ng/ml.

A Guide to Calcium-Rich Foods

We all know that milk is a great source of calcium, but you may be surprised by all the different foods you can work into your diet to reach your daily recommended amount of calcium. Use the guide below to get ideas of additional calcium-rich foods to add to your weekly shopping list.

Produce Serving SizeEstimated Calcium*
Collard greens, frozen8 oz360 mg
Broccoli rabe8 oz200 mg
Kale, frozen8 oz180 mg
Soy Beans, green, boiled8 oz175 mg
Bok Choy, cooked, boiled8 oz160 mg
Figs, dried2 figs65 mg
Broccoli, fresh, cooked8 oz60 mg
Oranges1 whole55 mg
SeafoodServing SizeEstimated Calcium*
Sardines, canned with bones3 oz325 mg
Salmon, canned with bones3 oz180 mg
Shrimp, canned3 oz125 mg
DairyServing SizeEstimated Calcium*
Ricotta, part-skim4 oz335 mg
Yogurt, plain, low-fat6 oz310 mg
Milk, skim, low-fat, whole8 oz300 mg
Yogurt with fruit, low-fat6 oz260 mg
Mozzarella, part-skim1 oz210 mg
Cheddar1 oz205 mg
Yogurt, Greek6 oz200 mg
American Cheese1 oz195 mg
Feta Cheese4 oz140 mg
Cottage Cheese, 2%4 oz105 mg
Frozen yogurt, vanilla8 oz105 mg
Ice Cream, vanilla8 oz85 mg
Parmesan1 tbsp55 mg
Fortified FoodServing SizeEstimated Calcium*
Almond milk, rice milk, soy milk, oat milk fortified8 oz300 mg
Orange juice and other fruit juices, fortified8 oz300 mg
Tofu, prepared with calcium4 oz205 mg
Waffle, frozen, fortified2 pieces200 mg
Oatmeal, fortified1 packet140 mg
English muffin, fortified1 muffin100 mg
Cereal, fortified 358 oz100-1,000 mg
OtherServing SizeEstimated Calcium*
Mac & cheese, frozen1 package325 mg
Pizza, cheese, frozen1 serving115 mg
Pudding, chocolate, prepared with 2% milk4 oz160 mg
Beans, baked, canned4 oz160 mg

*The calcium content listed for most foods is estimated and can vary due to multiple factors. Check the food label to determine how much calcium is in a particular product.


–Show More +

  • Calcium and Vitamin D Supplement Safety Fact Sheet
  • Just the Facts: Latest Evidence-Based Research on Calcium from the National Institutes of Health (NIH) Office of Dietary Supplements (ODS)

Last Reviewed 5/23/2023

How vitamin D and calcium work and why it is better to use them in pairs

Doctor tells






Do not self-medicate! In our articles, we collect the latest scientific data and the opinions of authoritative health experts. But remember: only a doctor can diagnose and prescribe treatment.

Advertisements urge us to buy and drink vitamin D and calcium supplements and assure us that this will solve many health problems. Is this true, or is the general obsession with these elements just the result of successful pharmaceutical marketing? Larisa Gennadievna Bavykina, an endocrinologist and nutritionist, a geneticist at the Atlas Medical Center , answers a controversial question.

What is Vitamin D? Pediatricians at the beginning of the 20th century began to recommend spending at least 15 minutes a day in the sun and consuming cod liver oil regularly.

At the beginning of the 21st century, numerous studies were carried out that contributed to the popularization of vitamin D. Scientists have found that it has an unusual structure for vitamins and affects many processes in the body. In addition, vitamin D is similar to a hormone in that it has receptors in various organs and tissues. For example, in osteoblasts (young bone cells). And vitamin D receptors in the gut help absorb calcium.

The basis of vitamin D is cholesterol, so this vitamin can penetrate into all cells of the body.

Production methods

  • Direct sunlight. The arms should be bare to the middle of the shoulder, the face and neck should be open. If these conditions are met for 5-15 minutes 2-3 times a week in the morning or evening, you will provide the body with vitamin D in the summer. But the abuse of sunlight – sunburn – is already harmful to health and increases the risk of skin cancer.
  • Vitamin D fortified milk or fish oil. Milk is irradiated on a conveyor belt with an ultraviolet lamp, and a precursor of vitamin D is formed from cholesterol. Fish oil is obtained from cod liver, which is naturally rich in this vitamin.
  • Preparations. Aqueous and oil solutions of vitamin D. This is a priority method of obtaining this vitamin in our time in the autumn, winter and spring periods.

Vitamin deficiency

You should not prescribe this vitamin yourself, especially since the symptoms of its deficiency are nonspecific and may indicate other pathologies.

Ask an endocrinologist or general practitioner to prescribe the drug in late summer – early autumn, if possible, take an analysis for vitamin D levels. The doctor will determine what dose of this vitamin to prescribe – preventive or saturating.

In addition, according to recent studies, the absorption of vitamin D is influenced by certain genes, more precisely, the genes “supervise” the work of various enzymes involved in the absorption of vitamin D. Thus, the DHCR7 gene regulates the work of the enzyme 7-dehydrocholesterol reductase, which is necessary for the synthesis vitamin D precursor. The CYP2R1 gene is responsible for liver enzymes involved in vitamin D metabolism. The GC gene regulates the activity of a protein that binds and transports this vitamin and its metabolites in the liver. Because of this complex system, it turns out that people under the same living conditions have different levels of vitamin D, which depends on genetic characteristics.

Vitamin D has a positive effect on the immune system, helps maintain bone density and prevents osteoporosis.

Benefits of calcium

Calcium is involved in a variety of body processes:

  • important for bone metabolism;
  • supports bone strength;
  • helps melatonin formation;
  • provides muscle contractions and conduction of nerve impulses.

To prevent calcium deficiency, fermented milk products should be consumed, and products marked “fortified with calcium” are also acceptable. With a lack of calcium, the body “takes” it from the bones, and they become “leaky”, the risk of fractures increases and osteoporosis develops.

Where to look for calcium

Calcium and vitamin D are interconnected: milk and dairy products contain bioavailable calcium, but it is well absorbed only when there is enough vitamin D in the body. Only in commonwealth of these two elements reduce the risk of developing osteoporosis.

Calcium is found not only in dairy products, but also in nuts, nut milk, green vegetables (spinach, broccoli, etc.). The problem is that 100 g of hard cheese contains the same amount of calcium as 1 kg of broccoli and 15 kg of spinach. Therefore, it is easier to get the necessary element from fermented milk products or medicines prescribed by a doctor.

What vitamin ensures the absorption of calcium in the body


Contents of the article

  • What effect does calcium have on the human body?
  • What vitamin ensures the absorption of calcium in the body?
  • What foods are the best sources of calcium absorption
  • What foods flush calcium out of the body
  • Sources

Calcium (Ca) is one of the few elements that is necessary for almost every cell. Without it, the full formation of tissues and the normal course of biochemical processes are impossible. The body cannot synthesize Ca on its own. Food and special additives provide its replenishment.

But in order to replenish the reserves, it is not enough to receive the necessary doses of the microelement. You also need to create conditions for its assimilation. A number of useful substances contribute to this process. What vitamin ensures the absorption of calcium and what is the role of this nutrient?

What effect does calcium have on the human body?

The distribution of Ca in the body is uneven – 99% of the element is contained in the teeth and bones, and only 1% is distributed to other organs. The substance comes in from the outside, and its excretion is provided by the kidneys and intestines.

Functions performed by Ca:

  • Balances the processes of excitation and inhibition in the cerebral cortex
  • Necessary for bone formation and mineralization of teeth
  • Affects the heart rhythm and blood clotting
  • Participates in the formation of many hormones and enzymes;
  • Helps to strengthen the immune system

The substance provides bone strength. At the same time, bone tissue acts as a kind of depot for its storage. With a deficiency of an element, the body begins to use these reserves. Prolonged removal of the mineral from the bones leads to osteoporosis, deterioration of the central nervous system (CNS) and heart, tooth decay, and the development of allergic reactions.

Ca deficiency in children is manifested by metabolic disorders, pathological formation of the musculoskeletal system and teeth, and poor sleep.

The need for the mineral depends on age. In addition, gender, lifestyle, and the presence of diseases matter. Large doses of the nutrient (up to 1500 mg) are necessary for women during pregnancy, breastfeeding, postmenopausal women.

However, an excess of the substance can also lead to health problems. The use of more than 2.5 mg of calcium per day causes a deterioration in appetite, constipation, increased blood pressure (BP), convulsions, and increases the risk of calculus formation. Therefore, the mineral should enter the body only in the required quantities. And for its full assimilation, it is necessary to take preparations additionally enriched with other vitamins and microelements.

What vitamin ensures the absorption of calcium in the body?

Ca absorption is a complex process, for which vitamin D is primarily important. It improves the absorption of the mineral in the small intestine and helps strengthen bones. With a lack of vitamin, calcium can be poorly absorbed even when taken in the right quantities.

In addition, vitamins act as a support group:

  • C – accelerates the maturation of collagen, which acts as a natural support for bone tissue, skin, blood vessels. Protects blood vessels and the heart, prevents the development of allergies.
  • B6 – improves the absorption of magnesium, necessary for the full functioning of the central nervous system.
  • K1 – prevents osteoporosis. Together with vitamin D, it is involved in the synthesis of osteocalcin, which helps to retain calcium. Reduces the risk of fractures.

Minerals are also needed for better absorption of Ca: magnesium (Mg), phosphorus (P), zinc (Zn), iodine (I).

Fully provide the body’s need for calcium and its maximum assimilation of such combined preparations as Calcium D-3 Nikomid-Forte, Calcemin, Osteogenon. But you can take them only as prescribed by a doctor. In the absence of the opportunity to consult with a specialist, stocks can be replenished with food.

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All products Pyridoxine (Vitamin B6)

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From which foods calcium is best absorbed

Many foods are rich in calcium. To replenish the body with a mineral, you need to include in the diet:

  • Sesame seeds – most Ca contains seed coats, so you need to use unpeeled seeds. Peeled sesame seeds practically do not bring benefits.
  • Milk and dairy products – the element is best absorbed from pasteurized milk. UHT and sterilized dairy products contain much fewer substances that help good absorption of Ca.
  • Greens, vegetables, nuts, berries and fruits – compared to milk, they have less calcium. The element is best absorbed from raw vegetables and fruits.

Combining these products, you can provide the body with the necessary amount of the substance. However, Ca is easily washed out. Therefore, it is necessary not only to saturate the body with a mineral, but also to prevent its leaching.

All products Calcemin

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All products Calcium-D3 Nycomed

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All products Osteogenon

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contribute to its leaching from the bone tissue. These include:

  • Palm oil – prevents the absorption of calcium and many useful substances.
  • Coffee – flushes Ca and other minerals from the body. No more than 4 cups of coffee with a capacity of 30 ml are allowed per day.
  • Sweets – disturb the intestinal microflora, in which all useful substances are absorbed.
  • Sweet water – also disrupts the functioning of the intestines and interferes with the absorption of the trace element. Some drinks contain caffeine, which washes away beneficial elements.

In addition, products with a high salt content, animal fats, and all alcoholic beverages interfere with the absorption of the mineral and contribute to its leaching.