If you don’t take a magnesium supplement, chances are you are magnesium deficient, unless you eat 6 or more servings of vegetables every day along with seeds and nuts. According to the Food and Nutrition Board, the RDA for magnesium varies with age but is approximately 400 mg for adult men and 320 mg for adult women, but almost no one gets that much from modern day diets.
Magnesium deficiency has been associated with cardiovascular disease, hyper tension, diabetes and osteoporosis.
Institute of Medicine (US) Standing Committee on the Scientific Evaluation of Dietary Reference Intakes. Dietary Reference Intakes for Calcium, Phosphorus, Magnesium, Vitamin D, and Fluoride. Washington (DC): National Academies Press (US); 1997.
Repeated studies show the average American has inadequate intakes of magnesium.
Magnesium consumption is particularly low among adolescent females, adult females, and elderly men, with one study showing that 85%, 80%, and 75%, respectively, of the population groups having mean magnesium intakes below their respective RDA.
In one NHANES study, none of the African Americans studied met the RDA for magnesium.
Fulgoni V 3rd, Nicholls J, Reed A, Buckley R, Kafer K, Huth P, DiRienzo D, Miller GD. Dairy consumption and related nutrient intake in African-American adults and children in the United States: continuing survey of food intakes by individuals 1994-1996, 1998, and the National Health And Nutrition Examination Survey 1999-2000. J Am Diet Assoc. 2007 Feb;107(2):256-64.
In another study, the actual intakes of magnesium were 202 mg/day for children from 1 to 5 years old, 228 mg/day for women and 331 mg/day for men, well below the RDA for all the groups.
For older Americans, a study showed that both men and women had median diet intakes below the RDA for magnesium. That is, less than half had adequate intakes.
According to the last Food and Nutrition Board’s review of magnesium, “Magnesium is a required cofactor for over 300 enzyme systems. It is required for both anaerobic and aerobic energy generation and for glycolysis, either indirectly as a part of the Mg-ATP complex or directly as an enzyme activator. Magnesium has also been shown to be required for mitochondria to carry out oxidative phosphorylation. The mitochondrial enzymes utilize the magnesium chelate of ATP and ADP as the actual substrates for phosphate transfer reactions.”
In other words, adequate magnesium is crucial.
As there is no magnesium guru in the world, no one person who is the magnesium expert, magnesium is what Professor Robert Heaney calls an “orphaned mineral.” No one is studying magnesium exclusively and thus there is no world expert on magnesium. Magnesium is involved in the metabolism of vitamin D and has complicated interactions with vitamin D and calcium.
Fatemi S, Ryzen E, Flores J, Endres DB, Rude RK. Effect of experimental human magnesium depletion on parathyroid hormone secretion and 1,25-dihydroxyvitamin D metabolism. J Clin Endocrinol Metab. 1991 Nov;73(5):1067-72.
Doctors mistakenly think that a blood magnesium level will assess magnesium stores in the body. However, serum magnesium is homostatically controlled, so assessing serum magnesium to assess total body magnesium stores makes about as much sense as measuring a serum calcium level to assess total body calcium stores. Measuring either tells you nothing unless total body stores are extremely low.
In my opinion, everyone should take a magnesium supplement with their vitamin D, at least 300 mg/day for men and 200 mg/day for women. While you may be one of the few with adequate dietary intake of magnesium (such as those who eat a lot of vegetables and seeds and nuts), it is more likely you are magnesium deficient. I believe magnesium supports vitamin D by acting as a cofactor in the enzymes that metabolize vitamin D.
If you are a graduate student interested in vitamin D, consider specializing in magnesium. You could eventually become the world’s magnesium guru like Professor Robert Heaney is the world’s calcium guru.