High doses of zinc in an additional form appear to interfere with the absorption of magnesium. One study has reported that zinc supplementation at a dose of 142 mg / day in healthy adult men significantly reduced magnesium uptake and disrupted the magnesium balance (the difference between magnesium intake and magnesium loss in the organism).
Vitamin D and Calcium
The active form of vitamin D(calcitriol) may slightly increase the absorption rate of magnesium in the intestine. However, it is not clear whether the absorption of magnesium is calcitriol-dependent, like absorption of calcium and phosphate. Most of the studies claim that high calcium intake doesn't affect the magnesium balance. It is known that insufficient levels of magnesium in the blood lead to low levels of calcium in the blood, resistance to the action of parathyroid hormone (PTH) and resistance to certain effects of vitamin D.
In experimental studies, it was found that a significant increase in fiber intake reduces the use of magnesium. However, the extent to which dietary fiber affects the nutritional state of magnesium in people with diverse diets outside the laboratory is unclear.
Dietary protein can affect the absorption of magnesium. In one study where the research was conducted on a group of teenage boys, it was found that magnesium absorption was lower when protein intake was less than 30 grams per day, and an increase in protein intake (93 g / day versus 43 g / day) was associated with improved absorption of magnesium.