Quote Originally Posted by Biciclista View Post
how much Vit D are you taking? what are your Vit D levels? (there's a test your doctor can do)
Yep, get your D-hydroxy levels tested. Also, consider that the most absorbable form of vitamin D is the animal form (D3 - cholecalciferol) from cod liver and other sources. Plant-based vitamin D (D2 - ergocalciferol) is not as well utilized by the body. I take these D Drops by Carlson's, which come from cod-liver. (I also take cod liver oil for the EFA benefits, but a serving of that usually has less than 1,000IU of D per dose.)

Also keep in mind that the current RDA for vitamin D is quite low and on the verge of being revised. The amounts you can get from normal dietary sources (even enriched with D) are generally not enough to correct a state of deficiency.

Many healthcare providers and nutritionists advocate against taking too much vitamin D (and the other fat soluble vitamins like A & E) because it is fat soluble. The upper tolerated limit of D is suspected to be 10,000IU per day. If you are exposed to bright sunlight in summer, your body does not manufacture more than this amount.

My own physician recommends 4,000-6,000IU in winter time, bumping that up to 8,000-10,000IU if I'm fighting off a cold/flu. In summertime I still take about 2,000IU daily because I work indoors and tend to avoid excessive sun exposure.