Magnesium deficiency in the rat: effects of fructose, boron and copper.

Magnesium (Mg) participates in many biochemical reactions which involve a variety of other nutrients. To elucidate some nutrient interactions, fructose (FR) and starch (ST) were compared as carbohydrate sources, and boron (B) and copper (Cu) were added to low-Mg diets for young male rats. Lack of Mg always caused characteristic deficiency symptoms. FR resembled Mg deficiency in effects on body, liver, and kidney weights and on plasma cholesterol level, but did not affect serum Mg or calcium (Ca). FR effects apparently were not mediated by changes in plasma Mg and Ca concentrations and were not prevented by adding Cu. B appeared to lessen effects of a low-Mg diet on body growth, serum cholesterol, and ash concentration in bone, but exacerbated deficiency symptoms, without affecting the concentration of Mg or Ca in serum. Results suggest that increased FR intake and marginal B might adversely affect individuals whose Mg status is suboptimal.