Historically, 400 IU (10 ug) of vitamin D was recommended for better health because it closely approximated the amount of vitamin D in a teaspoonful of cod liver oil. However, 800 to 1,000 IU is ...

If you’ve discovered you have a deficiency in vitamin D, you’re not alone. It’s particularly common among: people who get limited sun exposure people with dark skin people over 65 years old ...