In Brief: Vitamin C study

Vitamin C study: Recommended daily allowance (RDA) for vitamin C should be raised to 200 mg from 60 mg, researchers from the National Institutes of Health and Uniformed Services University of the Health Sciences conclude in a study published in the April Proceedings of the National Academy of Science USA. Mark Levine et al. noted that the 200 mg daily level can be reached by consuming fruits and vegetables. The researchers examined the link between vitamin C dose and plasma concentration, bioavailability, urinary excretion, cell concentration and potential adverse effects in seven healthy males. Safe doses are less than 1,000 mg daily and doses above 400 mg "have no evident value," they found...