Magnesium Deficiency in Pregnancy May Cause Insulin Resistance & Obesity in Offspring.

An animal study conducted under the auspices of the National Institute of Nutrition, India and published in the Journal of Nutrition (135:1353-8, 2005) found that restriction of maternal dietary magnesium during gestation appears to adversely affect the offspring's insulin function and glucose tolerance. Under the “fetal programming” hypothesis, impaired intrauterine development results in insulin resistance and associated metabolic disturbances. Researchers had observed increased body fat, a forerunner of insulin resistance, in the pups of mineral-restricted mother rats. In this study researchers sought to identify the effects of dietary magnesium restriction.

In the study group mother rats were fed a magnesium-restricted diet, and then the offspring were randomized to either a control diet or a magnesium-deficient diet. Pups of the magnesium-deficient mother rats had a higher percentage of body fat and plasma triglycerides and lower lean body mass than the control pups. By 180 days after birth, the pups from magnesium-deficient mothers showed insulin resistance and a lower response to a glucose tolerance test than control offspring, regardless of the magnesium content of their postpartum diets.

The researchers concluded that magnesium deficiency during pregnancy irreversibly increases body fat and induces insulin resistance in the offspring, while further magnesium deficiency after birth impairs glucose tolerance.