Folic Acid Supplementation in Children With Sickle-Cell Disease: A Randomized Double-Blind Cross-Over Trial

About the study

Folic acid supplementation (1mg/d) is the standard recommendation for Canadian children with Sickle cell disease (SCD), even though it can provide up to six times the recommended intake amount for healthy children. There is growing concern that too much folic acid can be detrimental to health as high folate levels and circulating unmetabolized folic acid (UMFA), which occurs in blood with doses of folic acid as low as 0.2mg/d, have been associated with accelerated growth of some pre-cancerous cells, and altered DNA methylation and gene expression.

To inform the efficacy and potential harm of high-dose folic acid supplementation in Canadian children with SCD, a double-blind randomized controlled cross-over trial is proposed. Children with SCD (n=36, aged 2-19 y) will be recruited from BC Children’s Hospital and randomized to initially receive 1 mg/d folic acid or a placebo for 12-weeks (wk). After a 12-wk washout period, treatments will be reversed.

Study point of contact

Brock Williams, MSc, RD
[email protected]
Crystal Karakochuk, PhD, RD
[email protected]


2 Years - 19 Years


Not Applicable

Study type





Dietary Supplement

participation requirements

Individuals with SCD aged 2-19 y attending British Columbia Children’s Hospital
Individuals having received routine daily supplementation of folic acid for the prior 12-weeks

participation restrictions

Individuals receiving a blood transfusion in the prior 12-weeks
Individuals allergic to any components of the supplement (cellulose, methylcellulose, magnesium stearate, and/or titanium dioxide)
Individuals presenting with megaloblastic anemia in the prior 12-weeks
Individuals with pulmonary, renal and/or cardiac complications (severe or recurrent acute chest syndrome)
Individuals routinely taking medications known to interfere with B vitamin metabolism (chloramphenicol, methotrexate, metformin, sulfasalazine, phenobarbital, primidone, triamterene, barbiturates)
Individuals who are currently pregnant, planning to become pregnant in the next 9-months, or currently breastfeeding
Individuals who have participated in a clinical research trial in the previous 30 days
Individuals who have donated blood in the previous 30 days
Individuals with unstable medical conditions or unstable laboratory results.

Last updated 2021-04-27