Why You Need It: Calcium, the most abundant mineral in the body, is essential for muscle contractions, a healthy nervous system, blood clotting, hormone secretion, and, of course, strong bones. Research also has shown that getting enough calcium can prevent osteoporosis (when combined with regular exercise and adequate levels of vitamin D); lower blood pressure; and reduce the risk of colorectal cancer.
How Much You Need
AGE (YEARS) MEN & WOMEN
1 to 3 500mg
Note: Don’t exceed 2,500 mg daily as excessive levels can hamper absorption of other minerals and, in rare cases, impair kidney function.
Good Food Sources
Dairy (yogurt, milk, cheese), sardines, canned salmon with bones (the canning process makes the bones soft and edible; just mash them with a fork), broccoli, bok choy, cabbage, fortified beverages like orange juice and soy milk, and tofu processed with calcium salt (look for calcium sulfate on the list of ingredients).
For Best Absorption…
- Take your it in divided doses, with each dose containing no more than 500 mg.
- You need vitamin D to absorb and use calcium. Get 1,000 IU of vitamin D daily, either through sun exposure (20 minutes of midday sun) or through supplements (vital in the low-light winter).
- Don’t take your supplements at the same time as foods containing high levels of calcium-blocking phytic acid (like wheat bran or oat bran) or oxalic acid (like spinach, rhubarb collard greens).
- Take calcium at separate times than iron supplements, since they compete for absorption.
The supplements come in two main forms:
- Calcium carbonate // Inexpensive and ubiquitous in supplements, this form needs to be taken with food for best absorption. Also, opt for “refined calcium carbonate,” since the unrefined form may contain lead.
- Chelated calcium // Like citrate, gluconate, or malate, though these cost extra, you absorb them better (especially citrate) and can take them on an empty stomach.
Ask the Expert
Robert P. Heaney, MD, mineral expert at Creighton University answers common questions about calcium.
Q: Do I get enough rom my multivitamin?
A: No. It is too bulky—a useful quantity of calcium would make the multi as big as a horse pill.
Q: Are chewable supplements just as good as tablets?
A: Yes, but remember: Calcium supplements should be just that—supplements to an otherwise good diet. For calcium to be helpful, your diet must be rich in protein, and your vitamin-D status must be optimal.