Stress-Axis Regulation by Vitamin D₃ in Multiple Sclerosis

Area of Science:

• Endocrinology
• Neuroimmunology
• Nutritional Science

Background:

• Multiple Sclerosis (MS) is linked to low vitamin D levels and heightened Hypothalamus-Pituitary-Adrenal (HPA) axis activity.
• Vitamin D3, a nuclear receptor ligand, may interact with the HPA axis, necessitating further investigation.

Purpose of the Study:

• To investigate the association between vitamin D3 supplementation and circadian cortisol levels in female patients with relapsing-remitting MS.
• To assess the impact of vitamin D3 on HPA axis activity, specifically focusing on daily cortisol patterns and the cortisol awakening response (CAR).

Main Methods:

• A double-blind, placebo-controlled study involving 41 female patients with relapsing-remitting MS.
• Participants received either 4,000 IU/day of vitamin D3 or a placebo for 16 weeks.
• Salivary cortisol levels (circadian rhythm and CAR) and serum 25(OH)D were measured before and after the treatment period.

Main Results:

• Vitamin D3 supplementation significantly increased serum 25(OH)D levels compared to placebo.
• No significant differences were observed in the overall daily cortisol curve (AUC and slope) between groups.
• A trend towards reduced cortisol awakening response (CAR) AUC was noted in the vitamin D3 group, though not statistically significant after baseline correction.

Conclusions:

• Vitamin D3 supplementation may influence HPA axis activity in non-depressed MS patients, potentially reflected in the CAR.
• Further research is warranted to elucidate the interaction between vitamin D3 and the HPA axis in MS and its clinical implications.