Iranian researchers randomly assigned 56 women with gestational diabetes to receive either 1,000 milligrams of calcium a day along with 50,000 units of vitamin D twice during the six-week study, or to get placebo pills. Blood samples were taken at the start and the end of the project. The analysis was published online in Diabetologia. In the supplement group, fasting blood glucose and cholesterol levels improved, measures that deteriorated in the placebo group. There was no effect on triglyceride levels.
The senior author, Dr Ahmad Esmaillzadeh, an associate professor at the Isfahan University of Medical Sciences, said that these supplements are not suitable for all women.