Influence of protein intake on magnesium requirement during protein synthesis.

Abstract

Adult protein-depleted rats receiving a complete mineral supplement gain over twice as much in 10 days on a 14% level of protein intake as on a 7% (120 mg N daily) level, but those receiving a Mg-deficient ration gain over twice as much on a 7% level of protein intake as on a 14% level. These results indicate that the Mg requirement for normal protein metabolism increases during protein synthesis as protein intake is increased from 7% to 14% and that the increased Mg requirement is not merely for the structural inclusion of Mg in new tissue. A 7% level of protein intake permits only a markedly subnormal rate of protein synthesis in a previously depleted animal, but 9% and especially 14% levels of protein intake insure more normal rates of protein synthesis and reveal the markedly deleterious effects of magnesium-deficient rations on protein synthesis within 10 days.