In one trial, taekwondo athletes were given 5,000 IU of vitamin D3 daily for a month during winter. The supplementation group had a much lower average score of respiratory tract infections, at just ...

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 ...

Why we chose it: Pure Encapsulations Vitamin D3 gets our pick as the best high ... supplement — at least 10,000 international units (IU) daily. This may be followed by a maintenance dose of ...

Several months ago, my doctor recommended I start taking 1,000 IU of vitamin D3 daily to support bone health. She also said research shows vitamin D may even help prevent breast cancer. I was like, ...