Associations of Serum Folate and Mental and Physical Health in Informal Caregivers

BACKGROUND: Emotional and physical demands of caregiving can affect nutritional intake, particularly of vitamin B9 (folate), which is important in the functioning of the nervous and skeletal systems. Non-caregivers studies in Puerto Rico, a folate-fortified region since 1998, have reported low consumption of folic acid (folate added to foods or taken as a diet supplement) consumption among women, which can potentially affect individuals' subjective mental/physical health well-being. Serum folate levels are a widely used, low-cost, modifiable marker of recent folate status, yet a relationship between serum folate levels and mental/physical health among informal caregivers of patients with chronic diseases in Puerto Rico has not been established. The latter study can be especially vital, as it may allow us to contribute to the initial understanding of caregivers' mental/physical health phenotypes. OBJECTIVE: To evaluate cross-sectional relationships between serum folate levels and subjective mental health and physical health in informal caregivers of patients with chronic diseases in Puerto Rico. METHODS: An observational cross-sectional study from July 2024 to May 2025 was conducted with 69 caregivers. Participants provided blood samples for serum folate levels and answered the PROMIS-10 questionnaire. Descriptive statistics, independent samples t-tests, and multiple regression models were conducted. RESULTS: The sample included 69 participants. In regression analyses, higher folate levels were significantly associated with higher mental health in both unadjusted and fully adjusted models. Folate levels were also positively associated with physical health in unadjusted and partially adjusted models; however, this association was attenuated and no longer statistically substantial after further adjustment for perceived stress. DISCUSSION: Findings suggest that low serum folate levels are a risk factor to consider while assessing the physical/mental health of informal caregivers, with future studies aimed at validating the findings in a larger cohort and with future clinical applications such as screening for folate deficiency, dietary counseling, and supplementation programs to address and mitigate these specific health risks.