Food sources of vitamin D are limited but include fish (cod liver oil has the highest), eggs, and fortified dairy products. The best source of vitamin D is the sun. All it takes is 20-30 minutes a day of exposing large areas of skin for Caucasians to get adequate levels of vitamin D. It can take 3-6 times more for darkly pigmented skin. When my family and I head out in the sun we rarely use sunscreen which can block vitamin D formation in the skin. If we're going to be out for a long day in the sun during the summer I wait 20-30 minutes after we've been out before I apply natural, chemical-free sunscreen.
The best way to determine whether or not you need oral supplementation is to test your blood levels of the active form of vitamin D, 25(OH)D. Most labs reference ranges are around 25-60 ng/ml. Labs make this determination based on levels from the general population. However, it's thought that 70% of the general population is deficient, so this is not an accurate reference for ideal levels. Optimal levels are in the range of 50-80 ng/ml.
- vitamin D 2,000 IU
- vitamin A 3,000 IU
- vitamin K 100 µg
- tocotrienols 5 mg