Calcium Absorption Is Affected by Dietary Fat and Fiber - Brief Article

Vegetarian Journal, Jan, 2001 by Reed Mangels

Two people can have the same amount of calcium in their diets but can differ widely in the amount of calcium they are able to absorb. The amount of calcium that is absorbed is much more important than the amount of calcium in the diet because only calcium that is absorbed is available to our bodies for bone maintenance and other key functions.

What factors affect calcium absorption? A study of 142 women between 45 and 54 years old examined this question. None of the women had osteoporosis. Factors that appeared to significantly affect the amount of calcium absorbed by study subjects included dietary fat, dietary fiber, alcohol, and blood levels of vitamin D. Women with the lowest ratio of dietary fat to dietary fiber absorbed significantly less calcium than did women with a high ratio of dietary fat to dietary fiber. This suggests that a lowfat, high-fiber diet can reduce calcium absorption. The authors note that other studies indicate that only wheat bran fiber reduces calcium absorption, although they were not able to determine so in this study. Women whose diets are high in fiber, especially wheat bran fiber, and low in fat, may need to be especially aware of good sources of calcium. Additionally, even moderate use of alcohol appeared to reduce calcium absorption slightly, as did low blood vitamin D levels. Many factors affect calcium absorption and bone status. This study suggests that dietary fat and fiber play a role.

Wolf RL, Cauley JA, Baker CE, et al. 2000. Factors associated with calcium absorption efficiency in pre-and perimenopausal women. Am J Clin Nutr 72:466-471.