Vitamin B12 and folate status during pregnancy among Saudi population

Abstract

T2DM is a growing health problem worldwide. It is now increasingly being diagnosed earlier in life. The factors involved in such an epidemic are complex. The intrauterine environment has long been known as an important contributor to many diseases including metabolic disorders such as T2DM. Recently, there is emerging evidence for maternal micronutrients affecting vital developmental processes in utero which can adversely “programme” the offspring to develop metabolic disorders in later life. Thus, “gene-diet” interaction during foetal development is likely to be a significant contributor to the epidemic of T2DM. In particular, the intrauterine imbalance between the two related vitamins, vitamin B12 and folate, affect DNA methylation and in turn programme the foetus for the whole life. Evidence from mandatory folic acid fortification studies suggests that in the presence of adequate folate, neural tube defects due to vitamin B12 insufficiency have tripled. In India, children born to mothers with “high folate and low vitamin B12” had higher adiposity and insulin resistance. Therefore, micronutrient status during pregnancy is likely to have a significant impact on the metabolic risk of the offspring. This thesis examines whether vitamin B12 insufficiency is prevalent in pregnancy, especially in a non-vegetarian population across the world as well as the Saudi pregnant population. As estimated intake is an accepted measure for micronutrient levels, we also examined the relationship between estimated vitamin B12 and folate intake with actual levels in the blood. We have found that vitamin B12 insufficiency was not uncommon during pregnancy across the world even in the non-vegetarian population and is also common in the Saudi population. Surprisingly, vitamin B12 insufficiency was observed in 50% of the tested population even in the presence of adequate vitamin B12 intake. In addition, we have also shown for the first time in the Saudi population that maternal BMI is inversely related to vitamin B12 levels, particularly in pregnancy. Even though we have shown a similar (or worse) picture in mothers with gestational diabetes, this study needs to be replicated, as our numbers are too small. Prospective studies linking the role of vitamin B12 insufficiency especially in the presence of high folate on birth outcomes in the Saudi population as well as intervention studies investigating the role of vitamin B12 supplementation in women of childbearing age and in pregnancy are urgently needed