Vitamin D: Bolus Is Bogus-A Narrative Review

Area of Science:

• Endocrinology
• Nutritional Science
• Public Health

Background:

• Vitamin D is crucial for bone health and immune function.
• Controversy exists regarding optimal vitamin D dosing strategies (bolus vs. daily).
• Current evidence suggests potential risks associated with high-dose bolus vitamin D administration.

Purpose of the Study:

• To review the impact of bolus versus daily vitamin D dosing on 25(OH)D and 1,25(OH)2D levels.
• To evaluate the efficacy of different vitamin D dosing regimens for various health outcomes.
• To identify potential biases in vitamin D health recommendations due to inconsistent trial data.

Main Methods:

• Systematic review of existing literature on vitamin D dosing.
• Analysis of studies comparing bolus versus daily vitamin D administration.
• Examination of cellular mechanisms and countervailing factors affecting vitamin D function.

Main Results:

• Bolus vitamin D dosing may lead to suboptimal 25(OH)D and 1,25(OH)2D levels compared to daily dosing.
• Evidence suggests lack of efficacy or potential harm from bolus vitamin D for outcomes like respiratory infections, COVID-19, rickets, falls, fractures, and cancer.
• Daily modest dosing has shown efficacy in vitamin D-deficient individuals where bolus dosing has failed.

Conclusions:

• Bolus vitamin D dosing strategies require critical re-evaluation.
• Daily vitamin D supplementation at modest levels appears more effective and safer for most health outcomes.
• Inconsistent data from trials combining bolus and daily dosing may skew public health recommendations.