Influence of narrowband ultraviolet B phototherapy on serum folate level in skin of color females: A cross-sectional study

Abstract

Background: Narrowband ultraviolet B (NB-UVB) (311–312 nm) is widely used for dermatological conditions with a favorable side-effect profile during pregnancy. Recently published data showed that NB-UVB might decrease serum folate level in Fitzpatrick skin phenotype I–III, especially at higher doses; this may predispose newborns to neural tube defects. Objective: To compare serum folate levels of skin of color females treated with NB-UVB and healthy females of childbearing age, as well as to note whether subsequent complications have been observed, if any. Methods: Multicenter, cross-sectional study of 30 females (N = 30): 15 female patients undergoing NB-UVB phototherapy as well as 15 age-, gender-, and skin phenotype-matched healthy volunteers who were enrolled into the study after excluding factors known to alter serum folate concentration. NB-UVB exposures were performed 2–3 times a week for at least 8–12 weeks (mean cumulative NB-UVB dose ± standard deviation [SD] was 55 ± 79 J/cm2). Results: Mean serum folate ± SD in NB-UVB exposed and healthy controls were 10.3 ± 4 and 8.3 ± 3 ng/mL, respectively. This was not a statistically significant difference between the 2 groups (P = .14). Limitations: Small sample size (N = 30) and a cross-sectional study type. Conclusion: Cumulative NB-UVB exposure is not associated with a statistically significant difference in serum folate level (P > .05) in skin of color females of childbearing age in comparison to age-, gender-, and skin phenotype-matched healthy females, even with the relatively higher cumulative doses (mean ± SD was 55 ± 79 J/cm2) that have been shown to reduce serum folate level in lighter skin phenotypes.