Calcium from natural food better than from dietary supplement

To avoid osteoporosis, natural cancer more effective than calcium dietary supplemental tablets.

24 June, 2007: Calcium from natural food is certainly better for the body than calcium that comes from supplemental tablets.
Women who get most of their daily calcium from food have healthier bones than women whose calcium comes mainly from supplemental tablets, according to researchers at Washington University School of Medicine in St Louis, the United States. This is true even though those who take calcium supplement have a higher average intake of calcium.

Sufficient calcium is needed to prevent osteoporosis, a disease which affects about 8 million women and 2 million men in the United States. Another 34 million Americans have low bone mass, placing them at increased risk for osteoporosis.

Calcium consumption can help maintain bone density by preventing the body from ‘stealing’ the calcium it needs from the bones.

The conclusions of the research on calcium intake have been published in the American Journal of Clinical Nutrition.

The study covered 183 post-menopausal women. The researchers asked the women to detail meticulously their diet and their calcium supplement intake for a week.
The researchers found that the women could be divided into three groups: one group, called the ‘supplement group,’ got at least 70% of their daily calcium from tablets or pills; another, the ‘diet group,’ got at least 70% of their calcium from dairy products and other foods; and a third, the ‘diet plus supplement group,’ consisted of those whose calcium source percentages fell somewhere in between these ranges.

The ‘diet group’ took in the least calcium, an average of 830 milligrams a day. Yet this group had higher bone density in their spines and hipbones than women in the ‘supplement group’ who consumed about 1,030 milligrams a day. Women in the ‘diet plus supplement group’ tended to have the highest bone mineral density as well as the highest calcium intake at 1,620 milligrams a day.

The hormone estrogen is known to maintain bone mineral density, but the standard form of estrogen is broken down or metabolised in the liver to other forms – some active and some inactive. Analysis of urine showed that women in the ‘diet group’ and the ‘diet plus supplement group’ had a higher ratio of active to inactive estrogen metabolites than women in the ‘supplement group.’

This suggests that dietary calcium is associated with a shift in estrogen metabolism that favours production of active forms of estrogen,” says senior author of the study Dr Reina Armamento-Villareal, assistant professor of medicine in the Division of Bone and Mineral Diseases and a bone specialist at Barnes-Jewish Hospital.

Dr Reina Armamento-Villareal adds: “Though it is not yet certain what underlies this effect, it could be that nutrients other than calcium cause this shift. It is also known that dairy products, which are a major source of calcium, can contain active estrogenic compounds, and these can influence bone density and the amount of estrogenic metabolites in the urine.”

Calcium supplements differ in how well their calcium can be absorbed, and this also could have played a role in the study’s findings. For example, calcium carbonate tablets need to be taken with a meal so that stomach acid can facilitate absorption, but calcium citrate tablets do not have this limitation.

If the participants of the study taking calcium carbonate were not conscientious about the timing of their supplements, they might not have received the highest benefit from them, the researchers say.

According to Armamento-Villareal, only about 35% of the calcium in most supplements ends up being absorbed by the body. Calcium from the diet is generally better absorbed, and this could be another reason that women who got a high percentage of calcium in their food had higher bone densities.

Though dairy foods are excellent sources of calcium, Armamento-Villareal suggests that those people who are sensitive to dairy products could consume other calcium-rich food sources like calcium-fortified orange juice and dark green leafy vegetables.