Serum folate and dietary folate intake in beta thalassaemia trait: a case-control study from Sri Lanka

Ineffective erythropoiesis, although at a mild degree, could make individuals with beta thalassaemia trait (BTT) vulnerable to folate deficiency. This could be more pronounced in communities where dietary intake of folate is substantially lower. We aimed to assess serum folate levels and dietary folate consumption in individuals with BTT and compare them with healthy matched controls.

A case-control study.

This study was conducted between June 2021 and June 2022 at a regional thalassaemia centre in Sri Lanka.

The study includes 100 sets of samples, including a BTT and an age-matched, sex-matched and body mass index-matched healthy individual from the same household in each set, aged between 6 and 25 years.

The primary outcomes were serum folate levels and the daily dietary intake of folate in BTTs and controls. Serum folate levels were determined using a fully automated Cobas immunoassay analyser. The dietary folate intake was determined by recording 24-hour dietary recall recorded over 3 consecutive days, with the average intake calculated.

The results suggested that 34% of cases and 24% of controls had serum folate deficiency (<3 ng/mL), while 37% of cases and 49% of controls were at risk (3-5.9 ng/mL) for folate deficiency. Overall, the serum folate level was not significantly different between the cases (mean; 4.88 ng/mL) and the controls (mean; 4.76 ng/mL) (p=0.759). Dietary folate intake was lower than the recommended dietary allowances in both groups, but not significantly different between the groups.

There were high levels of folate deficiency in both controls and those with BTT, while those with BTT were no more likely to be folate deficient than the controls. Based on our findings, a policy of indiscriminate folic acid supplementation for all with BTT does not seem rational.