Your body contains about 1.2 to 2.5 pounds of calcium. Most of it, 99 percent, is in your bones and teeth. The remaining 1 percent is distributed across your body in your cells, the membranes that encase your cells, your blood, and in other bodily fluids.

Most of us know that our bones and teeth are made primarily of calcium. But it’s not just any calcium. They’re made of calcium phosphate, a compound of calcium and phosphorous. Does this mean taking calcium phosphate supplements can give you healthier bones?

Calcium does more than build strong bones and healthy teeth. This remarkable mineral also:

  • helps blood vessels to regulate the flow of blood in your body
  • assists in the contraction of your muscles
  • aids in communication between nerve cells
  • contributes to blood clotting

In general, both men and women need about 1,000 milligrams (mg) of calcium per day.

Women should up their intake to 1,200 mg at about 51 years old. This is because bone breakdown in postmenopausal women is greater than the amount of bone formation.

Men should up their intake to 1,200 mg at about 71 years old.

Infants, children, and pregnant women have the greatest need for calcium because of their exceptional rates of bone formation and growth.

According to the National Institutes of Health (NIH), the recommended daily intake of calcium should be:

infants, birth to 6 months 200 mg
infants, 7 to 12 months 260 mg
children, 1–3 years old 700 mg
children, 4–8 years old 1,000 mg
children, 9–18 years old 1,300 mg
adult men, 19–70 years old 1,000 mg
adult men, 71 years and older 1,200 mg
adult women, 19–50 years old 1,000 mg
adult women, 51 years and older 1,200 mg

They say that milk can give you stronger bones and healthier teeth. But many other foods are good sources of calcium, too. Try adding more of these to your grocery list:

  • cheese, yogurt, and other dairy products
  • nuts and seeds
  • beans
  • broccoli
  • greens, such as spinach, kale, arugula, and collard greens
  • black-eyed peas
  • figs
  • oranges
  • tofu
  • salmon or sardines, canned, with bones

There is no such thing as a nugget of pure, elemental calcium. In nature, calcium is found bound with other elements, such as carbon, oxygen, or phosphorous. When one of these calcium compounds is digested, it returns to its elemental state, and your body reaps the benefits.

Calcium from dolomite, bone meal, or oyster shells isn’t recommended because these sources may contain lead and other toxins. Your body absorbs calcium better when you take it in small doses (500 mg or less) with food.

Calcium phosphate — which you find as tricalcium phosphate in supplements — contains close to 39 percent elemental calcium. This is just a fraction below calcium carbonate (40 percent), but well above calcium citrate (21 percent), calcium lactate (13 percent), and calcium gluconate (9 percent).

Taking vitamin D will help your body absorb calcium better. Many calcium supplements also contain vitamin D.

“In most cases, calcium phosphate offers no advantage over calcium carbonate or calcium citrate,” said Dr. Roger Phipps, assistant professor at Husson University School of Pharmacy. “However, adequate phosphate is needed for bone health. So calcium phosphate may be a more appropriate supplement in someone with phosphate deficiency.”

Phosphate deficiency is more common in those with celiac disease, Crohn’s disease, kidney issues, alcohol use disorder, and those who take too many antacids. However, most people get enough phosphorus in the average American diet.

Most people who need calcium supplements need it because of vitamin D deficiency. In fact, excess phosphate linked to cola or soda consumption is a growing health concern because it’s associated with osteoporosis and problems with kidney function.

Stick to natural sources when it comes to calcium, unless a doctor recommends otherwise. If getting enough calcium is a concern for you, calcium carbonate and calcium citrate are likely your best options.