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Specific Vitamins: Calcium

Calcium is an essential nutrient for health, fitness and wellbeing, but sufficient amounts of calcium are difficult to obtain from the diet alone, especially for women of all ages. Deficiencies of calcium contribute to osteoporosis, a condition where bones become porous and brittle.

What are the differences in various calcium supplements?

Studies have shown little difference in the absorption of calcium between different types of supplements. The absorption rate varies between 30-40% with calcium carbonate being close to the bottom and calcium bis-glycinate being near the top. However, since calcium carbonate is far cheaper, it is more cost effective simply to take a little more of it. We suggest that you avoid both dolomite and bone meal supplements because they often contain large amounts of impurities, including lead.

Which kind of calcium is best for post menopausal women?

More important than selecting a particular calcium supplement is to take all the additional things that help calcium be absorbed and are also crucial to the maintenance of healthy bones and teeth. The most important of these are: magnesium, vitamin D3, zinc, copper, manganese, boron, silica, and vitamin K.

When should calcium be taken?

Calcium and these other supplements can be taken with or without meals. However, the oil soluble vitamins D and K are better absorbed if taken with meals.

The following interactions affect bioavailability of calcium:

  1. A high protein diet or high coffee consumption increases calcium excretion -- and therefore you need more calcium.

  2. Fiber, oxalates (in rhubarb, spinach, beets, celery, greens, berries, nuts, tea, cocoa), and high zinc decrease absorption -- and therefore you need more calcium.

  3. Lactose, other sugars, and protein increase absorption of calcium.


Sources: Paul Wakfer (was Tom Matthews)




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