Maternal B vitamin status in pregnancy week 18 according to reported use of folic acid supplements

Scope Epidemiological studies on the association between pregnancy outcomes and use of periconceptional folic acid are often based on maternal reported intake. Use of folic acid during pregnancy is associated with a higher socioeconomic status known to have an impact on diet quality. We have studied plasma B vitamin status according to reported use of folic acid supplements during the periconceptional period in N orwegian women. Methods and results Plasma levels of folate, cobalamin, pyridoxal 5′‐phosphate (vitamin B 6), riboflavin, and the metabolic markers total homocysteine, methylmalonic acid and 3‐hydro‐xykynurenine were measured in pregnancy week 18 and related to reported intake of folic acid from 4 weeks prior to conception throughout week 18 in 2911 women from the N orwegian M other and C hild C ohort S tudy ( M o B a) conducted by the N orwegian I nstitute of P ublic H ealth. Being a folic acid user during the periconceptional period was associated with a better socioeconomic status, and a higher intake of several micronutrients, including vitamins, trace‐metals, and omega 3 fatty acids. Folic acid users had a significantly better plasma B vitamin status. Conclusion Epidemiological data based on maternal reported intake of folic acid supplements during pregnancy, should take into account the numerous nutritional implications, in addition to higher blood folate levels, of being a folic acid user.