Oral vs. injected: which vitamin D boost works best for low levels?

Vitamin D is essential for maintaining bone and mineral balance. This study aims to identify the most effective route for achieving optimal vitamin D levels (≥30 ng/mL) to support bone and mineral health.

In this open-label randomized trial, 132 participants aged 18-60 with initial serum vitamin D levels below 30 ng/mL were divided into three intervention groups: daily 800 I.U. oral tablet (Group A), weekly 60,000 I.U. oral sachet (Group B), and monthly 300,000 I.U. intramuscular injection (Group C). The study assessed changes in their serum vitamin D levels at six and 12 weeks.

The monthly intramuscular (IM) group consistently had the highest mean vitamin D levels at six weeks 38.38(±9.953) (p<0.002) and 12 weeks 48.15(±7.71) (p<0.001). Vitamin D insufficiency was reduced to 34.8 % at six weeks (p=0.434) and 6.8 % at 12 weeks (p=0.002). Notably, 100 % of the monthly IM group achieved vitamin D sufficiency at 12 weeks.

The monthly IM route demonstrated superior effectiveness compared to tablets and sachets at both the 6-week and 12-week points. A significantly larger number of monthly IM participants achieved vitamin D sufficiency compared to the other groups.