Breastfeeding mothers who take monthly high doses of vitamin D can improve the chances of their babies avoiding debilitating bone conditions, New Zealand health researchers said on Tuesday. There was growing concern internationally that the number of children suffering from vitamin D deficiency was increasing, University of Otago researcher Dr Ben Wheeler said in a statement. Vitamin D was essential for calcium and bone metabolism and was mainly obtained from exposure to sunlight, with only low levels found in food and breast milk. Risk factors for infant vitamin D deficiency, which can lead to the bone disorder rickets, included being exclusively breastfed. Many countries recommended giving babies daily vitamin D supplements during breastfeeding, but this advice was often not followed, said Wheeler. In a randomised controlled trial, 90 breastfeeding mother were divided into three groups, with the first group given a 1.25mg dose of vitamin D each month for four months, a second had a 2.5mg dose, and the third took a placebo. The study found a significant and clinically meaningful increase in vitamin D levels in the blood of infants whose mothers took the highest dose compared with those on the placebo. “At this dose, the improvement in vitamin D status appears to offer some protection against moderate to severe deficiency in infants, as only one of the babies in the 2.5mg group showed serious deficiency compared to six in the placebo group,” Wheeler said.