According to one older review, many experts agree that at least 1,000 IU (25 mcg) of vitamin D3 daily is needed in situations where there is no exposure to sunlight. Because vitamin D is fat ...

800 IU (20 mcg) per day increases vitamin D blood levels 8 ng/ml (20 nmol/L). 1000 IU (25 mcg) per day increases vitamin D blood levels 10 ng/ml (25 nmol/L). 2000 IU (50 mcg) per day increases ...

Pure Encapsulations Vitamin D3 gets our pick as the best high dose vitamin D option because it’s third-party tested and provides 10,000 IU per serving. If you have a severe vitamin D deficiency ...

A 21-year-old man or women exposed to summer UVB light generates 10,000 IU (the equivalent of 250 mcg, 25 multivitamin pills of vitamin D, or 100 glasses of milk) of vitamin D in 15 to 20 minutes.