The U.S. Preventive Services Task Force, a panel of experts appointed by the government, issued a report on vitamin D and calcium supplements. They may not help prevent bone fractures in older women, but will increase the risk of kidney stones.
According to Carolyn Dean, MD, ND, magnesium expert and Medical Advisory Board member of the nonprofit Nutritional Magnesium Association, adequate levels of magnesium in the body are essential for the absorption and metabolism of vitamin D and calcium. Magnesium converts vitamin D into its active form.
Absorption and metabolism of one nutrient will be affected by the other nutrients available to the body. According to the nonprofit Vitamin D Council, "In order to receive the most health benefit from increased levels of vitamin D, the proper cofactors must be present in the body. Vitamin D has many cofactors, but the ones listed here are the most important, with magnesium topping the list: Magnesium, Vitamin K, Vitamin A, Zinc and Boron."
A 32-page guide to the benefits of magnesium, written by Dr. Dean, is available as a free download at nutritionalmagnesium.org.
What this study tells us is taking supplements must be done based upon scientific research. Even if the body is deficient in one vitamin, other vitamins, minerals or nutrients may be needed to assist the deficient vitamin in its role in the body. A deficiency in vitamin D shouldn't be corrected simply by taking a vitamin D supplement. It may also be necessary to take a supplement for magnesium, Vitamins K and A, zinc and boron.
The best way to give the body the vitamins and minerals it needs is by eating healthy foods. These foods are highest in vitamin K: dried basil, sage, thyme, coriander, marjoram, oregano and fresh parsley; dark green leafy vegetables such as kale, scallions, Brussels sprouts, broccoli and asparagus; spices; chili peppers, curry, paprika and cayenne.
Foods rich in zinc include: oysters, roast beef, turkey, pumpkin seeds, wheat germ, soy nuts, almonds, peanuts, shrimp and chicken. Foods containing vitamin A include spinach, broccoli, sweet potato and carrots.