Response to short‐term folic acid intake in relation to the body composition of women of reproductive age

Abstract

Epidemiological studies have reported maternal obesity and folic acid status in early pregnancy as risk factors for neural tube defects in the offspring, but the current RDA for folic acid for women of childbearing age is 400 mcg irrespective of weight or adiposity. The aim of this study was to investigate the relationship between adiposity (%BF) and the short‐term pharmacokinetic response to an oral dose of folic acid in women of childbearing age. Thirty‐two healthy Caucasian females (mean age 25.78±5.02 yrs) were administered 400 mcg of folic acid orally after an overnight fast, blood samples were collected for 10 hours post dose to measure serum folate. Participant body composition was assessed using the BOD POD and subsequent analysis was performed according to %BF (normal < 32%, n=12; high ≥ 32% n=20). There was significant difference between %BF and baseline red blood cell (RBC) folate (p=0.046) with participants with high %BF having higher RBC folate levels, but not baseline serum folate (p=0.411) although, participants with normal %BF had slightly higher serum folate levels. Serum folate response differed between normal %BF and high %BF, with a higher post dose peak observed for participants with normal %BF. Our findings suggest the rate of absorption and distribution of folic acid in women of childbearing age is influenced by adiposity and may need to be considered in folic acid intake recommendation to reduce the risk of NTD in the offspring of obese women.