Vitamin B status was inversely associated with incident metabolic syndrome among Black and white young adults in the U.S., according to an analysis of the CARDIA study published in JAMA Network Open.

“To the best of our knowledge, data remain unavailable on the longitudinal association of these B vitamin intakes with the development of metabolic syndrome among the general population of adults in the U.S.,” Jie Zhu, MD, PhD, assistant professor in the nutrition and foods program at the School of Family and Consumer Sciences at Texas State University, and colleagues wrote.

This prospective study included 4,414 Black and white young adults (mean age, 24.9 years; 52.8% women; 50.4% Black) in the U.S. aged 18 to 30 years from four metropolitan areas in 1985 and 1986. Researchers assessed diet through a validated diet history at years 0, 7 and 20 and assayed serum concentrations of folate, vitamin B6 and vitamin B12 at years 0, 7 and 15. Researchers identified metabolic syndrome through laboratory measurements and self-reported medication use.

Overall, there were 1,240 incident metabolic syndrome cases during the 30 years of follow-up. When adjusted for potential confounders, incident metabolic syndrome was significantly lower for those with the highest vs lowest quintiles of B vitamin intake: folate (HR = 0.39; 95% CI, 0.31-0.49; P < .001), vitamin B6 (HR = 0.61; 95% CI, 0.46-0.81; P = .002) and vitamin B12 (HR = 0.74; 95% CI, 0.58-0.95; P = .008).

Similarly, incident metabolic syndrome was significantly lower for those with higher vs lower of serum concentrations: folate (HR = 0.23; 95% CI, 0.17-0.33; P < .001), vitamin B6 (HR = 0.48; 95% CI, 0.34-0.67; P < .001) and vitamin B12 (HR = 0.7; 95% CI, 0.51-0.96; P = .01).

“The robustness of our findings is supported by the consistent results of intakes and serum concentrations of these B vitamins,” the researchers wrote. “The findings of serum B vitamin concentrations are consistent with a case-control study that reported lower plasma vitamin B6 concentrations in Nigerian metabolic syndrome patients and cross-sectional studies that found inverse associations between blood folic acid, vitamin B6 and vitamin B12 and metabolic syndrome prevalence in various populations.”