Vitamin B12, Folate and Homocysteine Levels in the U.S. Urban Minority Mothers Post Delivery

Abstract

Mandatory folic acid fortification of grain products was implemented in the U.S. in 1998 and routine clinical recommendation on prenatal folic acid supplementation for pregnant women began as early as 1992. Yet there is a dearth of current data on folate, vitamin B12 and homocysteine (Hcy) levels in the U.S. urban minority mothers.Blood samples (obtained 2‐3 days post‐delivery) from 2,057 mothers 16‐51 y old enrolled in the Boston Birth cohort (during 1999‐2012) were analyzed for plasma folate, plasma vitamin B12 and Hcy levels. The percentage of self‐reported prenatal multi‐vitamin use during 3 month preconception, 1st, 2nd and 3rd trimester were 4.4%, 86.2%, 90.4%, and 88.5%, respectively. The plasma folate and B12 levels were significantly associated with prenatal multi‐vitamin intake in the 2nd and 3rd trimesters. Only 1.6% of the total samples had folate deficiency (<7 nmol/l) and 2.2% vitamin B12 deficiency (<150 pmol/l); but 20.8% had elevated Hcy levels (> 10 μmol/L). Consistent with the NHANES 2003‐06 data, black women had the lowest geometric mean of folate levels: 26.8 nmol/L and the highest vitamin B12 level: 282.5 pmol/L. Black women also had the highest Hcy: 7.9 μmol/L. The highest quartile of B12 was a significant predictor of elevated Hcy, after adjusting for age, race, smoking, alcohol, education and folate levels (p=0.001).This study underscores the need to improve preconception multivitamin intake and optimize B‐vitamin status in black mothers. The significantly higher percentage of elevated Hcy in black mothers (22.7%) compared to other racial/ethnic groups warrants further investigation.Research Support: In part by NICHD (R01 HD041702)