Cobalt competes with iron for absorption. Coffee, tea, milk, soy, tannins, zinc and manganese may reduce iron absorption while protein and particularly vitamin C enhances it. Absorption may be impaired with hypochlorhydria. Vitamin A deficiency impairs iron mobilization and utilization in the body. May increase cholesterol and triglyceride levels.
Magnesium citrate is more soluble and bioavailable than magnesium oxide.
Iron, calcium, fat, manganese and phosphorus decrease intestinal absorption while vitamin D increases absorption. Vitamin D though enhances calcium absorption more, and tissue calcium may displace magnesium enhancing a functional deficiency. Alcohol, caffeine, sugar, potassium and sodium increase urinary excretion. Folic acid may increase the metabolic need for magnesium by inducing glycolytic enzyme activity requiring magnesium and high protein diets as well as sugar also require increased magnesium. High dose riboflavin may increase the risk of magnesium deficiency.