How much vitamin D should you take?
The Institute of Medicine (IOM) has set a recommended dietary allowance for vitamin D. Getting this amount of vitamin D from diet, with or without supplements, should be enough to keep you healthy.
- 600 IU (international units) a day for anyone aged 1-70
- 800 IU/day for anyone over 70
Recently the IOM reviewed more than 1,000 research papers on vitamin D and concluded that high levels of the supplement are unnecessary and could be harmful.
The IOM warned that doses above 4,000 units a day were potentially harmful and that doses above 10,000 IU per day are associated with kidney and tissue damage.
Can you get vitamin D naturally from foods?
The best source of natural vitamin D is sunlight. Just 10 to 15 minutes of exposure without sunscreen a couple of times a week usually gives you enough vitamin D.
Vitamin D is also naturally found in butter, eggs, and fish such as salmon, tuna and mackerel. Vitamin D is often added to fortified foods, too, such as milk and cereal.
What are the risks of taking vitamin D?
- Side effects. At normal doses, vitamin D seems to have few side effects.
- Interactions. Vitamin D can interact with many medicines, such as drugs for high blood pressure and heart problems. If you take daily medicine, ask your health care provider if it's safe for you to take vitamin D supplements.
- Risks. Too much vitamin D can cause loss of appetite, frequent urination, and weight loss. High doses of vitamin D can also lead to disorientation and kidney and heart problems.