>Interventions: Daily doses of vitamin D3 for 3 years at 400 IU (n = 109), 4000 IU (n = 100), or 10 000 IU (n = 102). Calcium supplementation was provided to participants with dietary intake of less than 1200 mg per day.
>Main Outcomes and Measures: Co-primary outcomes were total volumetric BMD at radius and tibia, assessed with high resolution peripheral quantitative computed tomography, and bone strength (failure load) at radius and tibia estimated by finite element analysis.
>Conclusions and Relevance: Among healthy adults, treatment with vitamin D for 3 years at a dose of 4000 IU per day or 10 000 IU per day, compared with 400 IU per day, resulted in statistically significant lower radial BMD; tibial BMD was significantly lower only with the 10 000 IU per day dose. There were no significant differences in bone strength at either the radius or tibia. These findings do not support a benefit of high-dose vitamin D supplementation for bone health; further research would be needed to determine whether it is harmful.
Headline is not imprecise according to above-cited Conclusions and Relevance.
> Headline is not imprecise according to above-cited Conclusions and Relevance.
No, aladoc99 is right, because the study doesn't compare against 0. So you don't know if 4000 and 10000 improve strength compared to 0, only that they don't compared to 400. It's not a hill that someone should die on, though.
If you avoid animal foods the only dietary vitamin D really is from fortified products. However we also synthesize it, albeit poorly as adults, particularly with lower exposure to the sun.
>Main Outcomes and Measures: Co-primary outcomes were total volumetric BMD at radius and tibia, assessed with high resolution peripheral quantitative computed tomography, and bone strength (failure load) at radius and tibia estimated by finite element analysis.
>Conclusions and Relevance: Among healthy adults, treatment with vitamin D for 3 years at a dose of 4000 IU per day or 10 000 IU per day, compared with 400 IU per day, resulted in statistically significant lower radial BMD; tibial BMD was significantly lower only with the 10 000 IU per day dose. There were no significant differences in bone strength at either the radius or tibia. These findings do not support a benefit of high-dose vitamin D supplementation for bone health; further research would be needed to determine whether it is harmful.
Headline is not imprecise according to above-cited Conclusions and Relevance.