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The synergistic effect of Calcium and Vitamin D

The synergistic effect of Calcium and Vitamin D

Remember when you were younger and your mom would pester you to finish your glass of milk at supper before you could go play with your friends? If you were like me, you’d sit there and begrudgingly down the glass whilst listening to a lecture on how important milk was for your bone health. It wasn’t until years later that I got into a serious accident, broke my foot, and realized, as mothers are 99% of the time, that she was right.

            Milk is a nutrient rich food that contains one of the most important macro minerals for bone structure, calcium. Calcium has many important bodily functions. It plays a role in nerve conduction, muscle excitation and contraction, blood clotting, metabolism, and most importantly bone structure. Adequate calcium intake is especially important during adolescence because our calcium absorption is at its highest. Once we reach the age of about 25, our bones reach their maximal density and our peak bone mass is reached. After this point, the cells involved in bone deposition, osteoclasts, begin to function at a slightly higher rate than the cells involved in bone formation, osteoblasts. Over time, this leads to a loss in bone mass that may result in osteoporosis. Women are at a greater risk of developing osteoporosis due to the link between estrogen and calcium absorption. The hormone estrogen aids in calcium absorption but once menopause is reached in women, the amount of estrogen in the body decreases, thus making it even more difficult for bone formation. Although the rate of decomposition begins to exceed the rate of bone formation as we age, especially in women, daily consumption of calcium can reduce the effects of decomposition.

            The recommended daily intake of calcium is 1,000 – 1,300 mg/day. Intake should be spread throughout the day because the rate of calcium absorption plateaus at 500 mg, causing side effects if any excess of calcium is consumed at one point in time.  Calcium supplementation may be used to reach the RDI, but the consumption of whole foods that contain calcium is preferred. The main foods that are rich in calcium include dairy products (milk, cream, butter, cheese), dark green vegetables (spinach, kale, okra), beans, peas, cauliflower, and egg yolks.

Along with adequate calcium intake, it is important to have sufficient amounts of Vitamin D in the body because it plays a role in promoting the absorption of calcium in to the small intestine. Vitamin D can mostly be found through exposure to the UVB rays of the sun, with typically a small amount coming from the diet. While adequate dietary intake is important for bone formation, exercise also plays a large role in increasing bone density. It has been found that muscle contraction and the performance of weight bearing activity promotes the deposition of calcium into bones.

            To lessen the effect of bone deposition as an adult, an aim toward a maximal peak bone mass should be of focus in adolescence. For those of us that have surpassed the point of increasing our peak bone mass, an adequate amount of calcium and vitamin D should be regularly consumed along with exercise to lessen the effects of bone deposition associated with aging.





Taylor Donald

B.S. Biochemistry, Exercise Physiology

University of Miami




            Jeukendrup, A., Gleeson, M. (2019). Sport Nutrition: Nutrients and Recommended Intakes. 3rd edition.
Ross A, Taylor, C, et al. (2011). Dietary Reference Intakes for Calcium and Vitamin D. National Center for Biotechnology Information. Retrieved from