By now you may be aware of the critical importance of getting enough vitamin D, not just for your bones, but to help ward off killer diseases such as heart disease, diabetes and cancer. However, you may not know that that vitamin D, whether from sunshine or supplements, may not be utilized properly if certain co-factor nutrients are lacking. The most important of these co-factors is the mineral magnesium.
The most recent National Health and Nutrition Examination Survey reported in the "Journal of Nutrition" indicates that a substantial number of Americans fail to consume adequate magnesium in their diets. A high calcium intake can decrease magnesium absorption, while many drugs, particularly diuretics, can adversely affect magnesium status. Furthermore, prolonged exercise can result in loss of magnesium through sweat and urine.
How Low Magnesium Affects Vitamin D Levels
According to a review of the interaction between magnesium and vitamin D in "Magnesium Research," a deficiency of magnesium is usually associated with low production of active vitamin D metabolites or by-products. Magnesium is necessary to activate all the enzymes that metabolize vitamin D. For example, it's now known that vitamin D regulates hundreds of human genes, including those genes linked to major diseases such as cancer and diabetes. Magnesium is required in the synthesis of DNA, the genetic blueprint of your cells, and it is also needed for vitamin D's actions in switching certain genes on or off.
Magnesium Dependent Vitamin D Resistance
Severe vitamin D deficiency in children results in rickets, a disease that softens and weakens bones. In a case reported in the "Lancet," two children with rickets received massive doses, 6 million IU of vitamin D over 10 days, without any improvement after six weeks. When they were treated with magnesium because of low serum levels, the rickets promptly disappeared. In another case study published in "The American Journal of Clinical Nutrition," vitamin D treatment did not resolve low blood calcium in five patients. Vitamin D is essential for calcium absorption. The patients were given magnesium because of low levels, and, as a result, the calcium levels quickly returned to normal. According to the study's authors, magnesium may promote the release of calcium from bone in the presence of vitamin D.
Getting Enough Magnesium
The best food sources of magnesium include nuts, dark leafy green vegetables, legumes, whole grains and fish. However, because of losses from cooking, processing and soil depletion, magnesium supplements may be helpful to ensure you're getting enough. This is especially important if you are taking calcium supplements without magnesium. The recommended daily allowance for magnesium is 420 mg/day for men and 320 mg/day for women.
- "Journal of Nutrition"; Dietary Magnesium Intake in a National Sample of U.S. Adults; Earl S. Ford and Ali H. Mokdad; September 2003
- "Lancet"; Magnesium-Dependent Vitamin D-Resistant Rickets; Vinodini Reddy and B. Sivakumar; May 1974
- "The American Journal of Clinical Nutrition"; Vitamin D Resistance in Magnesium Deficiency; Ramon Medalle et al.; August, 1976
- Vitamin D Council: Understanding Vitamin D