At least 5000 IU a day should be sufficient.
At least 5000 IU a day should be sufficient.
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Generally, it’s not recommended to exceed the upper limit of safe intake, which is 4,000 IU (100 mcg) per day.
How Much Vitamin D Is Too Much?
https://www.healthline.com/nutrition/how-much-vitamin-d-is-too-much
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I think that the optimum vitamin d blood level is 32 ng/ml. There are more kidney stones among people who have a level of 50 ng/ml. People who take 100 micrograms per day have a blood level of 67 ng/ml.
Vitamin D3 supplementation (4000 IU/d for 1 y) eliminates differences in circulating 25-hydroxyvitamin D between African American and white men
https://academic.oup.com/ajcn/article/96/2/332/4576869
RESULTS
The 2 groups were essentially indistinguishable after 1 y of vitamin D3 supplementation (67.7 compared with 67.3 ng/mL in African Americans and whites).