Women aged 19 to 50 need 1,000 mg of calcium per day. After age 50, that number rises to 1,200 mg to offset the accelerated bone loss that comes with menopause. These recommendations, set by the National Institutes of Health, stay at 1,200 mg for women over 70 as well.
Calcium Needs by Age
The daily target depends on your life stage:
- Ages 19 to 50: 1,000 mg
- Ages 51 to 70: 1,200 mg
- Over 70: 1,200 mg
The jump at 51 reflects what happens hormonally during menopause. Declining estrogen levels speed up the rate at which bone breaks down, and the extra 200 mg helps compensate. If you’re in perimenopause and unsure where you fall, the higher target is a reasonable goal.
During Pregnancy and Breastfeeding
Calcium needs don’t actually change during pregnancy or breastfeeding for women over 18. You still need 1,000 mg per day. Your body adapts by absorbing calcium from food more efficiently during pregnancy, and bone mineral temporarily lost during breastfeeding is typically restored after weaning. Teen mothers are the exception: those 18 and younger need 1,300 mg daily because their own skeletons are still developing.
Best Food Sources of Calcium
Dairy is the most concentrated source, but it’s far from the only option. Here’s what common foods deliver per serving:
Dairy and Fortified Alternatives
- Plain nonfat yogurt (8 oz): 488 mg
- Fortified almond milk (1 cup): 442 mg
- Low-fat milk (1 cup): 305 mg
- Fortified soy milk (1 cup): 301 mg
- Greek yogurt, plain, low-fat (8 oz): 261 mg
Non-Dairy Foods
- Tofu prepared with calcium sulfate (½ cup): 434 mg
- Fortified orange juice (1 cup): 349 mg
- Sardines, canned (3 oz): 325 mg
- Collard greens, cooked (1 cup): 268 mg
- Bok choy, cooked (1 cup): 185 mg
- Kale, cooked (1 cup): 177 mg
- Canned salmon with bones (3 oz): 181 mg
Two cups of milk and a serving of yogurt gets you close to 1,100 mg. If you’re dairy-free, a combination of fortified plant milk, tofu, and leafy greens can cover the same ground, though it takes more planning. One note on spinach: while it contains 245 mg per cooked cup on paper, its high oxalate content blocks most of that calcium from being absorbed. Kale, bok choy, and collard greens are much better plant sources.
When Supplements Make Sense
Food-based calcium is the preferred route, but if your diet consistently falls short, a supplement can fill the gap. The two most common forms are calcium carbonate and calcium citrate, and they differ in practical ways.
Calcium carbonate contains about 40% elemental calcium by weight, so you get more calcium per tablet. It needs stomach acid to absorb properly, so take it with a meal. Calcium citrate contains only 21% calcium, meaning you’ll need more tablets to hit the same number. The trade-off is that citrate absorbs well on an empty stomach and works better for people who take acid-reducing medications for heartburn or reflux.
Your body can only absorb a limited amount of calcium at once. Splitting your supplement into two doses of 500 mg or less, rather than taking it all at once, improves how much you actually retain.
The Role of Vitamin D
Calcium and vitamin D work as a pair. Vitamin D is what allows your intestines to absorb calcium efficiently. Without enough of it, you could hit your calcium target and still not benefit fully. Women up to age 70 need 600 IU of vitamin D per day. After 70, the recommendation increases to 800 IU. Many calcium supplements include vitamin D for this reason, which can simplify things if you’re already supplementing.
Risks of Too Much Calcium
More is not better. Excess calcium, particularly from supplements, carries real risks.
There is some evidence linking calcium supplements to a higher risk of heart disease, particularly in healthy postmenopausal women, though not all studies agree. A Mayo Clinic review noted that this concern applies specifically to supplements, not calcium from food. For women with diabetes, the risk may be more significant.
Kidney stones are another consideration, but the relationship is counterintuitive. The National Kidney Foundation recommends that people prone to calcium kidney stones should not cut calcium from their diet. Dietary calcium actually binds to oxalate in the gut and prevents it from reaching the kidneys, where it would otherwise form stones. Supplements, however, don’t offer this same protective timing unless taken with meals.
The practical takeaway: get as much calcium as you can from food. Use supplements only to close the gap between what you eat and what you need, not to pile on extra. If you’re eating a calcium-rich diet and already hitting 1,000 to 1,200 mg, adding a supplement on top could push you into territory where the downsides outweigh the benefits.