Investigation of Blood Folate and Vitamin B12 Levels in Women With Human Papillomavirus: A Systematic Review

Human papillomavirus (HPV) is a highly prevalent sexually transmitted infection. Discussions have arisen regarding reduced vitamin levels in patients. This review aims to gather evidence on blood folate and vitamin B12 levels in women with HPV.

A comprehensive search was conducted across multiple electronic databases, including Web of Science, Embase, Scopus, and PubMed, using keywords such as "human papillomavirus," "folate," and "vitamin B12". Combinations derived from MeSH and Emtree terms were also used. Boolean operators (AND, OR) applied without time restrictions, searching up to June 2024. Articles were selected based on inclusion and exclusion criteria, and the quality of included studies was evaluated using the Newcastle-Ottawa Scale, in accordance with PRISMA guidelines.

A total of 467 citations were retrieved, and nine studies (6 were cross-sectional and 3 were cohort studies) involving 15,978 participants were included in this systematic review. The studies exhibited significant heterogeneity in design and outcomes; therefore, a meta-analysis was not performed. Lower folate levels in HPV-positive women were reported in seven studies. Of the 6 studies assessing vitamin B12, 4 suggested an association with HPV infection, while 2 found no significant relationship.

The findings highlight an association between serum folate and vitamin B12 levels and HPV infection in women, although these observational data cannot rule out reverse causation. Further research is needed to clarify the causal relationship and underlying mechanisms.