From the Research
Effects of Administering 100,000 IU of Vitamin D3
- The administration of 100,000 IU of Vitamin D3 has been shown to increase serum 25-hydroxyvitamin D (25(OH)D) concentrations in several vitamin D-sufficient and -deficient populations 1.
- A study found that a single oral dose of 100,000 IU of vitamin D3 increased serum 25(OH)D3 levels above the 10 ng/ml threshold and maintained this level for three months in institutionalized elderly subjects 2.
- Another study investigated the effect of a single oral dose of 100,000 IU vitamin D3 on profiles of serum 25(OH)D3 and its metabolites, and found significant increases in serum concentrations of 25(OH)D3 and its metabolites 24,25(OH)2D3, 3-epi-25(OH)D3, and 1,25(OH)2D3 at 4 weeks 3.
- However, it is noted that vitamin D doses >500,000 IU should be used judiciously in order to minimize adverse events 1.
- The optimal dose of vitamin D3 for supplementation is still a matter of debate, but it is recommended that vitamin D3 be used for supplementation over vitamin D2, and that single vitamin D3 doses ≥300,000 IU are most effective at improving vitamin D status and suppressing parathyroid hormone (PTH) concentrations for up to 3 months 1.
Safety and Efficacy
- The safety and efficacy of administering 100,000 IU of Vitamin D3 have been evaluated in several studies, and no significant adverse events have been reported 2, 4, 3.
- A study found that long-term supplementation with vitamin D3 in doses ranging from 5000 to 50,000 IU/day appears to be safe, with no cases of vitamin D3-induced hypercalcemia or any adverse events attributable to vitamin D3 supplementation 4.
- However, it is important to note that individual responses to vitamin D supplementation can vary, and that any given dose of vitamin D is unlikely to achieve optimal vitamin D status in all treated individuals 3.
Specific Populations
- The effects of administering 100,000 IU of Vitamin D3 have been evaluated in specific populations, including institutionalized elderly subjects 2 and adults with vitamin D insufficiency 3.
- A study found that high-dose therapy of vitamin D3 may be effective in achieving optimal levels of serum 25(OH)D in adults with cystic fibrosis 5.