What is calcium?
Calcium is the most abundant mineral in the body, present mainly in the bones and teeth. It is an essential dietary element required in optimal amounts for good bone health, efficient nerve and muscle function, and overall cardiovascular health. It makes up about three percent of the earth's crust and is a basic component of most animals and plants. Our bones serve as a storage site for the body's calcium, providing this mineral to the bloodstream for use by the heart and other organs. Eating a diet rich in calcium helps to restore it to the bones; supplements can help as well.
Why is it necessary?
Calcium is known mostly for its role in building and maintaining strong bones and teeth, but it is also required for proper functioning of the heart, muscles and nervous system. It plays a role in maintaining normal blood pressure, regulating blood clotting, and preventing cancers of the digestive tract. It is also associated with relieving mood swings, food cravings, and decreasing the pain, tenderness and bloating associated with premenstrual syndrome (PMS).
What are the signs of a deficiency?
Symptoms of calcium deficiency (also known as hypocalcemia) range from minor - numbness or tingling of the fingers, muscle cramps, lethargy and poor appetite - to more severe, including mental confusion, skeletal malformations, dermatitis, and in infants, delayed development. Illnesses such as osteoporosis (brittle, thin, porous bones that easily break) and rickets are also associated with a deficiency.
How much, and what kind, does an adult need?
If vitamin D levels are optimal, most adults should be able to meet their daily calcium needs via a varied diet that includes a wide variety of calcium-rich foods. When individuals are unable to get enough calcium through their diet, or for those who may need more than the recommended daily allowance, supplements can help. Dr. Weil recommends women supplement with 500 to 700 mg of calcium citrate in two divided doses taken with meals for a total of 1,000-1,200 mg a day from all sources (including diet); for men Dr. Weil recommends not using calcium supplements at all (except on the advice of a physician), but instead getting 500-600 mg per day through diet. Dr. Weil suggests supplementing with calcium citrate, which is more easily absorbed than other forms, taken with half the dosage amount of magnesium.
How much does a child need?
According to the NIH, the normal daily recommended intake for children is as follows: infants through three years of age is 400-800 mg; children between 4 and 10 years of age is 800 mg; adolescent males is 800-1,200 mg; and adolescent females is 800-1,200 mg daily.
How do you get enough from foods?
An abundant source of this mineral in the American diet is dairy products - two glasses of milk per day provide 1,000-1,200 mg. If you choose to get your calcium via dairy products - and this is not essential, as there are many other sources - make sure you use only hormone-free, organic dairy products to reduce your exposure to the antibiotics and hormones found in many dairy products. Non-dairy foods rich in calcium include: greens such as collards, mustard, kale, and bok choy; canned salmon (with bones) and sardines; tofu that has been coagulated with a calcium compound; calcium-fortified soy milk, fruit juice and cereals; blackstrap molasses; and broccoli.
Are there any risks associated with too much?
Calcium supplements can be constipating, and should be balanced with magnesium as discussed above. Excessive amounts in the blood may have negative effects, including nausea, vomiting, loss of appetite, and increased urination. More serious complications include kidney toxicity, confusion, and irregular heart rhythm. Studies indicate that men who take too much may have an increased risk of prostate cancer, and should limit their dietary intake to 500-600 mg daily from all sources.
Are there any other special considerations?
- Vitamin D is key to absorbing and using calcium, so make sure to get adequate intake of vitamin D.
- Do not use bonemeal or dolomite as a source. The Food and Drug Administration has issued warnings that bone meal and dolomite could be dangerous because these products may contain lead.
- It is especially important that you are receiving enough when you become pregnant and that you continue to receive the right amount throughout your pregnancy as well as during breast feeding. Consult with your physician.
- Older people may need to take extra calcium or larger doses because they do not absorb it as well as younger people.
Updated by: Andrew Weil, M.D., and Brian Becker, M.D., on Sept. 10, 2012
Are you getting the supplements you need?
Everyone's dietary needs are different based on a number of factors including lifestyle, diet, medications and more. To find out which supplements are right for you, take Dr. Weil's Vitamin Advisor. This 4-step questionnaire requires just minutes to complete, and generates a free, no-obligation vitamin and nutritional supplement recommendation that is personalized to meet your unique nutritional needs.