B3(W)
DIETARY FOLATE INTAKE, FOLIC ACID SUPPLEMENTATION AND FOLATE
STATUS OF HAEMODIALYSIS PATIENTS
Duff, E1, Gillman, B2, O’Meara, Y2, Moloney, M1
1
School of Biological Sciences, Dublin Institute of Technology, 2Mater Misericordiae
University Hospital, Dublin
PROBLEM Impaired folate metabolism and inadequate folate status have been identified in
patients on Haemodialysis (HD). Current recommendations for folate intake in patients on HD
are 1000 µg daily (EBPG, 2007). Folic acid supplementation is commonly used in this patient
group to meet daily requirements, correct deficiencies and may also be used in the management
of hyperhomocysteinaemia, which is prevalent in this population. Given the paucity of
information in the renal literature on actual dietary folate intake and in light of recent studies
suggesting possible health risks with long term folic acid supplementation (Cole et al, 2007), it
was decided to assess actual folate intake and folate status in a HD patient group.
PURPOSE This study assessed total folate intake from natural food folate, foods fortified with
folic acid and folic acid supplements in HD patients as well as folate status by means of
biochemical analysis.
DESIGN Thirty-nine patients were recruited for this 12 week cross-sectional research study
(excluding patients on HD <3 months, those taking folic acid antagonistic medication, and those
who had a prolonged inpatient stay at the time of the study). Food diaries, including information
on foods fortified with folic acid, were completed by each patient and analysed using WISP
(V.3, 2007). Information on folic acid supplementation was documented. Single, non-fasting
serum folate (SF) and red cell folate (RCF) measurements were analysed for all patients. SPSS
(V.18.0) was used for statistical analysis.
FINDINGS All patients were on a routine prescription of a folic acid supplement. 33 patients
(Group A) received a 5000µg folic acid supplement once weekly and 6 patients (Group B)
received 5000µg daily
Table 1: Mean daily intake of total folate (µg), dietary folate (µg) and folic acid from
supplements (µg) for Group A and B.
Group
Total folate (µg)
Dietary folate (µg)
Folic acid from supplements (µg)
A
996.4 (±99)
282 (±99)
714
B
5229 (±146)
229 (±146)
5000
Mean values for SF were 34.3 (±39) µg/l and 199 (±222) µg/l and RCF 833 (±242) µg/l and 944
(±208) µg/l in Group A and B respectively. No patient was found to be folate deficient.
CONCLUSION Overall, dietary folate intake alone was insufficient to meet the recommended
daily intake of 1000µg. Patients taking a weekly folic acid supplement of 5000µg were at
recommended folate intakes, however patients taking a 5000µg folic acid supplement daily were
found to have intakes in excess of 1000µg.
RELEVANCE This study provides additional evidence on dietary and supplemental folate
intake in HD patients and also on biochemical folate status. Further research is required to
define optimal dose and frequency of folic acid supplementation in this patient group.
REFERENCES Fouque D, Vennegoor M, Wee PT et al (2007): European Best Practice
Guidelines on Nutrition (EBPG). Nephrol Dial Transplant, 22 Suppl 2, ii45-ii87.
Cole B, Baron J, Sandler R et al (2007): Folic acid for the prevention of colorectal adenomas (a
randomized clinical trial). JAMA. 297 (21) 2351-2359.