A PROSPECTIVE STUDY OF COMMONLY UTILIZED REGIMENS OF VITAMIN D REPLACEMENT AND MAINTENANCE THERAPY IN ADULTS

Area of Science:

• Endocrinology
• Nutritional Science
• Public Health

Background:

• Vitamin D deficiency is a widespread concern.
• Maintaining adequate 25-hydroxyvitamin D (25[OH]D) levels is crucial for health.
• Different vitamin D formulations and schedules may impact efficacy and safety.

Purpose of the Study:

• To compare the effectiveness and safety of various vitamin D doses, formulations (D2 vs. D3), and schedules.
• To identify the optimal regimen for achieving a target 25(OH)D level of >30 ng/mL.
• To evaluate the impact on parathyroid hormone (PTH) and calcium levels.

Main Methods:

• A prospective study randomized 100 participants with low 25(OH)D levels into four groups.
• Groups received cholecalciferol (D3) 2,000 IU daily, D3 3,000 IU daily, ergocalciferol (D2) 50,000 IU weekly, or D2 50,000 IU twice weekly.
• All participants received daily calcium carbonate supplementation; measurements included 25(OH)D, PTH, and urinary markers over 12 months.

Main Results:

• All four vitamin D regimens successfully raised mean 25(OH)D levels above 30 ng/mL within 5 months.
• The D2 50,000 IU twice-weekly group showed the most rapid increase, reaching target levels in 1 month and plateauing at 60 ng/mL.
• No significant hypercalcemia was observed; a negative correlation between vitamin D and PTH levels was noted.

Conclusions:

• All tested vitamin D replacement schedules were safe and effective in achieving and maintaining 25(OH)D levels >30 ng/mL.
• Ergocalciferol (D2) at 50,000 IU twice weekly demonstrated the fastest attainment and highest mean 25(OH)D levels.
• This regimen offers a potent option for vitamin D repletion.