Calcium is an essential mineral found throughout the body, with the largest amount stored in bones and teeth. It is widely recognized for its role in maintaining normal bone structure, but its functions extend beyond skeletal health.
The body also uses calcium for normal muscle contraction, nerve signaling, blood vessel function and other cellular processes. Because these functions require calcium on an ongoing basis, getting enough through food is an important part of balanced nutrition.
Calcium is naturally available in dairy products and a variety of other foods. It is also included in dietary supplements, either as a standalone mineral or alongside nutrients such as vitamin D, magnesium and vitamin K.
Calcium is a mineral and an essential nutrient, meaning the body needs it but cannot produce it on its own. It therefore has to come from food, beverages or supplements.
Most of the calcium in the human body is stored in bones and teeth. This stored calcium contributes to their structure while also serving as part of the body's calcium reserves.
A much smaller amount circulates in the blood and is present in other tissues, where it participates in several important physiological processes.
Calcium performs several functions beyond its familiar connection with bones.
It contributes to:
The body carefully regulates calcium levels in the blood because calcium is required for these processes. Bones also act as an important storage site for the mineral.
For this reason, adequate calcium intake is relevant throughout life, although individual requirements can vary with age and life stage.
Calcium is primarily obtained through everyday foods. Dairy products are among the best-known dietary sources, but calcium can also come from fish, vegetables, fortified foods and other sources.
When dietary intake is insufficient, calcium may also be consumed through supplements. It appears in products focused on bone nutrition as well as broader vitamin-and-mineral formulas.
Calcium supplements come in several forms, and the amount of elemental calcium provided can differ between them.
A varied diet can provide calcium from both animal and plant foods.
Common dietary sources include:
Some plant foods naturally contain calcium, although the amount the body absorbs can vary depending on other compounds present in the food.
Checking nutrition labels can help when comparing calcium content in fortified foods and beverages.
Calcium is available in several supplemental forms. Two of the most familiar are calcium carbonate and calcium citrate.
Calcium carbonate contains a relatively high proportion of elemental calcium. It is generally taken with food because stomach acid helps with its absorption.
Calcium citrate contains less elemental calcium by weight but can generally be taken with or without food. It may be used in products intended for people looking for an alternative to calcium carbonate.
Other forms of calcium can also appear in dietary supplements, including calcium phosphate, calcium lactate and calcium gluconate.
The name of the calcium compound and the amount of elemental calcium are not the same thing. Supplement Facts labels generally state the actual amount of calcium supplied per serving.
Calcium is included in supplements primarily because it is an essential mineral with established nutritional functions.
It frequently appears in:
Calcium is often paired with vitamin D because vitamin D contributes to normal calcium absorption. Some formulas also combine it with magnesium, vitamin K or other nutrients associated with bone and mineral nutrition.
The presence of several nutrients in one formula does not necessarily mean that everyone needs supplemental amounts of each one. Dietary intake and individual nutritional needs remain important considerations.
More calcium is not automatically better. Total intake includes calcium obtained from both food and supplements, so it is useful to consider dietary sources before adding a high-dose product.
Calcium absorption can also depend on the amount consumed at one time and the form being used. Following the serving instructions on the specific supplement is therefore important.
Calcium supplements can interact with certain medications and may affect the absorption of some medicines when taken at the same time. People taking prescription medications should check with a healthcare professional or pharmacist about appropriate timing.
People with kidney problems, a history of kidney stones, abnormal blood calcium levels or other relevant medical conditions should seek professional guidance before using calcium supplements.
Although calcium is closely associated with bones, only a small portion of the body's calcium is found outside the skeleton and teeth.
That small amount is still essential. The body uses it for functions such as muscle contraction, nerve communication and cellular signaling, which is why blood calcium levels are tightly regulated.
No. Calcium is important for maintaining normal bones and teeth, but it also contributes to muscle function, nerve signaling, blood clotting and several cellular processes.
Milk, yogurt, cheese, sardines with bones, canned salmon with bones and certain green vegetables can provide calcium. Many plant beverages and other foods are also fortified with the mineral.
They are two different calcium compounds used in supplements. Calcium carbonate contains more elemental calcium by weight and is generally taken with food, while calcium citrate can usually be taken with or without food.
Elemental calcium refers to the actual amount of calcium supplied by a calcium compound. This is the amount that matters when comparing calcium intake between supplements.
Yes. Calcium and vitamin D are frequently included together because vitamin D plays an important role in normal calcium absorption and bone health.
Supplements can provide additional calcium when needed, but they do not provide all of the nutrients and other components found in a varied diet. Food sources can remain an important part of overall nutrition.
Yes. Calcium can affect the absorption or use of certain medications. Anyone taking prescription medicine should check with a healthcare professional or pharmacist before using a calcium supplement or changing the timing of their medication.
Calcium is an essential mineral involved in bone and tooth structure as well as normal muscle, nerve and cellular function. Dairy foods, certain fish, vegetables and fortified foods can all contribute to dietary calcium intake.
Supplemental calcium is available in several forms, including calcium carbonate and calcium citrate. When considering a supplement, the amount of elemental calcium, existing dietary intake and other nutrients in the formula are useful factors to review.
Calcium needs vary between individuals and across different stages of life. A balanced diet and an appropriate overall nutrient intake provide the foundation for maintaining normal calcium nutrition and everyday wellness.
Supplements Containing Calcium