A pilot trial examining the absorption of oral forms of folate supplementation in a healthy population: A randomised control trial

Background & aims: Folate supplements are commonly prescribed by health professionals for a number of different conditions, however, the absorption of the different derivatives remains unclear. This pilot trial aims to assess the absorption of various forms of folate supplements in a healthy population. Methods: A four-week, single blinded, randomised control trial was conducted on 30 healthy individuals. The intervention included supplementation with 500mcg of either folic acid, folinic acid or 5-Methyltetrahydrofolate (5-MTHF). Fifteen participants were allocated to the intervention and fifteen to the control group for comparison. At baseline (week 0) a case report was completed and pathology tests for serum folate, B12 and MTHFR polymorphisms were conducted. Follow up serum folate blood pathology tests were assessed at week 2 and week 4 along with additional food diaries. Results: Of the cohort, 87% (n = 26) were found to have a MTHFR polymorphism with both A1298C (n = 12) and C677 T (n = 18) being tested. Only13% (n = 4) of participants had no mutation. The different MTHFR mutations were observed across both the control group and all of the intervention groups. The mean (+/- SD) baseline folate was 33.7 nmol/L +/- 7.55 (Reference range: >9.0). Participants who had both A1298C and C677 T polymorphism had lower baseline folate with a mean (+/- SD) of 29 nmol/L +/- 8.75. During the four weeks an overall increase in mean serum folate was observed in both the folinic acid and 5-MTHF group. The folinic acid intervention saw a mean (+/- SD) increase of 15.3 nmol/L +/- 3.56 and 5-MTHF saw a mean (+/- SD) increase of 9.1 nmol/L +/- 1.67, however a decrease in mean serum folate was detected in the folic acid group. In the folinic acid and 5-MTHF groups, serum folate increases were observed in individuals irrespective of their MTHFR status. Conclusions: This research has provided a foundation for further work investigating folate absorption. The results of the trial suggest that folinic acid has the best absorption, however, it may not have the best bioavailability. More research is required for greater clarification regarding the absorption and bioavailability of these supplements. (C) 2018 Elsevier Ltd. All rights reserved.