Would a person taking a calcium & magnesium combination supplement be receiving sufficient magnesium?
A. Probably not. Most calcium & magnesium combination supplements contain at least twice as much calcium as magnesium, and some of these products even contain up to 4 or 5 times as much calcium as magnesium. Numerous human studies have shown that high intakes of calcium such as this can actually inhibit magnesium absorption: Study Link – The effect of a high intake of calcium on magnesium metabolism in normal subjects and patients with chronic renal failure. Study Link – Increased need for magnesium with the use of combined oestrogen and calcium for osteoporosis treatment. Quote from the above study: High dietary Ca/Mg ratios interfere with Mg absorption, partially because Ca and Mg share a common intestinal absorption pathway… Vitamin D favours Ca over Mg absorption. Some studies also show that when calcium intake is in significant excess of magnesium intake, magnesium is excreted from the body at an accelerated rate. The following study found that at the intake of approximately 1000
