Vitamin B6 status is related to disease severity and modulated by endurance exercise in individuals with multiple sclerosis: a secondary analysis of a randomized controlled trial.

BACKGROUND

Low circulating concentrations of B vitamins are linked to various chronic and neurodegenerative diseases. Notably, pyridoxal 5'-phosphate (vitamin B6) deficiency is linked to altered inflammatory responses and cellular immune function, both critical in multiple sclerosis (MS). Nevertheless, most MS research has focused on folate (vitamin B9) and vitamin B12, leaving other B vitamins understudied.

OBJECTIVES

This secondary analysis investigated B-vitamin serum concentrations and related metabolites across MS phenotypes (primary progressive MS, relapsing-remitting MS, and secondary progressive MS) and disease severity levels. Additionally, the impact of endurance exercise on B-vitamin concentrations was investigated.

METHODS

In total, 106 individuals with MS participated in a randomized controlled trial, including different endurance exercise conditions. Serum B-vitamin concentrations were analyzed in 99 participants before and after 3 wk of intervention. Before analysis, participants were dichotomized to 1 of the 2 disability groups based on their expanded disability status scale (EDSS) score: EDSS≥4.5 (n = 47, EDSS: 5.86 ± 0.56) and EDSS<4 (n = 52, EDSS: 3.59 ± 0.83).

RESULTS

Higher EDSS scores were associated with lower pyridoxal 5'-phosphate (vitamin B-6) concentrations (rs: -0.32; 95% CI: -0.49, -0.12; P = 0.011), with the EDSS≥4.5 group also showing lower baseline pyridoxal 5'-phosphate (vitamin B6) concentrations (β: -0.18; 95% CI: -0.30, -0.07; P = 0.007) than the EDSS<4 group. Significant time × EDSS group interactions were evident for pyridoxal 5'-phosphate (vitamin B6; β: 0.05; 95% CI: 0.02, 0.08; P = 0.011), pyridoxal (vitamin B6; β: 0.05; 95% CI: 0.02, 0.09; P = 0.005), and riboflavin (vitamin B2; β: 0.06; 95% CI: 0.02, 0.09; P = 0.008), showing increases in these vitamers in the EDSS≥4.5 group postexercise. N1-Methylnicotinamide (vitamin B3; β: -0.11; 95% CI: -0.15, -0.06; P < 0.001) decreased in both groups over time.

CONCLUSIONS

Disease severity is associated with distinct B-vitamin profiles in individuals with MS, although endurance exercise appears to modify specific B-vitamin concentrations. This trial was registered at clinicaltrials.gov as NCT04356248.