Do high blood folate concentrations exacerbate metabolic abnormalities in people with low vitamin B-12 status?
Item Type:Journal Article
Citation:Mills JL, Carter TC, Scott JM, Troendle JF, Gibney ER, Shane B, Kirke PN, Ueland PM, Brody LC, Molloy AM., Do high blood folate concentrations exacerbate metabolic abnormalities in people with low vitamin B-12 status?, American Journal of Clinical Nutrition, 94, 2, 2011, 495 - 500
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ABSTRACT Background: In elderly individuals with low serum vitamin B-12, those who have high serum folate have been reported to have greater abnormalities in the following biomarkers for vitamin B-12 defi- ciency: low hemoglobin and elevated total homocysteine (tHcy) and methylmalonic acid (MMA). This suggests that folate exacerbates vitamin B-12–related metabolic abnormalities. Objective: We determined whether high serum folate in individuals with low serum vitamin B-12 increases the deleterious effects of low vitamin B-12 on biomarkers of vitamin B-12 cellular function. Design: In this cross-sectional study, 2 507 university students provided data on medical history and exposure to folic acid and vitamin B-12 supplements. Blood was collected to measure serum and red blood cell folate (RCF), hemoglobin, plasma tHcy, and MMA, holotranscoba- lamin, and ferritin in serum. Results: In subjects with low vitamin B-12 concentrations ( , 148 pmol/L), those who had high folate concentrations ( . 30 nmol/L; group 1) did not show greater abnormalities in vitamin B-12 cellular function in any area than did those with lower folate concentrations ( 30 nmol/L; group 2). Group 1 had significantly higher holotrans- cobalamin and RCF, significantly lower tHcy, and nonsignificantly lower ( P = 0.057) MMA concentrations than did group 2. The groups did not differ significantly in hemoglobin or ferritin. Compared with group 2, group 1 had significantly higher mean intakes of folic acid and vitamin B-12 from supplements and fortified food. Conclusions: In this young adult population, high folate concen- trations did not exacerbate the biochemical abnormalities related to vitamin B-12 deficiency. These results provide reassurance that folic acid in fortified foods and supplements does not interfere with vitamin B-12 metabolism at the cellular level in a healthy population.
Health Research Board (HRB)
National Institutes of Health (NIH)
Author: MOLLOY, ANNE
Type of material:Journal Article
Series/Report no:American Journal of Clinical Nutrition
Availability:Full text available
Keywords:low serum vitamin B-12,
Subject (TCD):International Development