London: Over-supplementing Vitamin A in your diet may decrease bone thickness, leading to weak and fracture-prone bones, a new study claims. Vitamin A found in meat, dairy products and vegetables, is an essential source that is important for growth, vision, immunity and organ function.

The findings showed that mice which were given lower doses of Vitamin A, equivalent to 4.5-13 times the recommended daily allowance (RDA) in humans, showed thinning of their bones in just eight days.

“Overconsumption of Vitamin A may be an increasing problem as many more people now take vitamin supplements. Overdose of Vitamin A could be increasing the risk of bone weakening disorders in humans but more studies are needed to investigate this,” said Ulf Lerner, Professor from Sahlgrenska Academy at the University of Gothenburg in Sweden.

“In the majority of cases, a balanced diet is perfectly sufficient to maintain the body’s nutritional needs for Vitamin A,” Lerner added.

Previous studies on mice have shown that short-term overdosing of Vitamin A, at the equivalent of 13-142 times the RDA in people, results in decreased bone thickness and an increased fracture risk after just one or two weeks. However, these studies were performed with very high doses of Vitamin A, over a short period of time.

“In our study we have shown that much lower concentrations of Vitamin A, a range more relevant for humans, still decreases rodent bone thickness and strength,” Lerner noted. Researchers suggested that people should be cautious of over-supplementing Vitamin A in their diets.

SOURCE : http://www.bfirst.in/big-story/overdose-of-vitamin-a-may-up-bone-fracture-risk-521183