 The study by Krishnaveni et al raises an intriguing possibility for a simple measure for preventing GDM and future T2D. It is believed that the high prevalence of B12 insufficiency in India was attributed to vegetarianism. As the majority of the UK population is non-vegetarian, it is conceivable that B12 deficiency is unlikely during pregnancy. However, the investigators have recently shown: a B12 deficiency is not uncommon in women of childbearing age 14 and pregnant women 20 at 16-18 weeks of pregnancy and b B12 deficiency in GDM is associated with higher BMI and higher birth weight in a clinic population. 