Abstract
It has been hypothesized that ultraviolet (UV) radiation can lead to depletion of plasma folate and B(12) vitamin, but few studies have investigated effects of other parameters of solar and geomagnetic activity (SGA). We investigated the association between four SGA parameters-interplanetary magnetic field (IMF), sunspot number (SSN), K(p) index, and ground shortwave solar radiation (SWR)-and three plasma B-complex vitamins-folate, B(6), and B(12)-in 910 participants from the Normative Aging Study (NAS) between 1998 and 2017. Mixed-effects regression models were used for 1- to 28-moving day averages of SGA exposure, adjusted for covariates. We compared the impact of SGA in individuals under higher and lower B-complex supplementation (> or < 50th quartile). Our findings show that increases in solar activity variables IMF and SSN were found to be significantly associated with decreases in B(12) vitamin. IMF and SSN were associated with decrease in folate levels, especially in individuals under higher levels of B-complex supplementation. No associations were found for SWR and K(p) index. To our knowledge, this is the first study that demonstrated the detrimental impact of solar activity on plasma B(12) and folate in a large cohort. These findings have clinical implications during periods of high solar activity.