So how much do you need each day? The recommended daily allowance is 600 IU for everyone under age 70, but this is based on bone health support and assumes minimal sunlight. Many nutritionists and physicians believe that is not enough due to the recently discovered receptors mentioned above; they now recommend 1,000 to 3,000 IU per day.
What's the best way to get enough vitamin D? Sun exposure is the best source - this should be limited to 10 to 15 minutes a day to get a therapeutic dose (note that sunscreen inhibits the amount of vitamin D the body can absorb). In addition, dietary supplements can help you get the right amount of vitamin D. Choose the cholecalciferol version (D3), which is more bioavailable than ergocalciferol (D2).
Vitamin D is naturally found in some foods:
- All varieties of mushrooms contain some vitamin D. The types with the most vitamin D include portobello, white button and cremini. One cup contains 380 IU of vitamin D.
- Two egg yolks contain 80 IU of vitamin D, making this one good reason to actually eat the yolk. Egg yolks also contain lutein, choline and vitamins A and E.
- Fatty fish, such as mackerel, sardines and salmon, contain 400-800 IU of vitamin D in one 4-ounce piece of fish.