Acute Homeostatic Changes Following Vitamin D₂ Supplementation

Area of Science:

• Endocrinology
• Nutritional Science
• Metabolism

Background:

• Vitamin D binding protein (DBP) and 24,25-dihydroxyvitamin D (24,25D) levels may influence vitamin D metabolite concentrations and bioavailability after supplementation.
• Understanding these changes is crucial for optimizing vitamin D therapy.

Purpose of the Study:

• To investigate the acute effects of vitamin D2 supplementation on vitamin D metabolism and bioavailability.
• To analyze changes in DBP, vitamin D metabolites, and bioavailable 25-hydroxyvitamin D (25D) following ergocalciferol treatment.

Main Methods:

• Secondary analysis of a single-arm interventional study.
• Thirty participants received five 50,000 IU oral doses of ergocalciferol over two weeks.
• Serum samples were analyzed for DBP, vitamin D metabolites, and bioavailable 25D before and after treatment.

Main Results:

• Supplementation significantly increased 25D2, total 25D, DBP, total 24,25D, bioavailable 25D, and 1,25D.
• 25D3 levels decreased post-supplementation.
• No significant changes were observed in calcium or parathyroid hormone levels.

Conclusions:

• Vitamin D2 supplementation leads to an acute increase in serum DBP and 24,25D.
• These increases may potentially moderate the rise in bioavailable 25D and 1,25D.
• Further research is needed to fully elucidate the implications of these metabolic shifts.