Up to $500m a year could be put to better use by stopping ineffective and potentially harmful supplementation programmes in poorer countries, argues John Mason, professor emeritus at Tulane University School of Public Health and Tropical Medicine.

However Keith West, professor of infant and child nutrition at Johns Hopkins Bloomberg School of Public Health disagrees, saying that such programmes have been proved to save millions of lives and should be withdrawn only when robust evidence permits.

Read the full head to head debate:
http://www.bmj.com/content/360/bmj.k927