It is essential to maintain healthy vitamin D levels throughout all stages of life, from fetal development to old age.* Vitamin D helps protect a number of important functions in the body.* The current recommended daily vitamin D intake ranges from 200-600 IU and is based on the minimum allowance to protect against bone disease. However, an upward revision of the FDA's guideline is now under consideration in light of new research, especially pertaining to immune function. Cutting-edge research suggests serum vitamin D levels should be in the range of 32-80 ng/mL 25-hydroxyvitamin D (25(OH)D). Although direct sunlight exposure is a good source of vitamin D, many people do not get enough sun due to season change, latitude, or lifestyle. Therefore, vitamin D supplementation can be of great benefit in these cases.*

Vitamin D deficiency is quite common, particularly among the elderly.* For example, a study conducted at a hospital in Glasgow, Scotland, found an almost universal vitamin D deficiency among a group of 548 elderly patients. Individuals deficient in vitamin D may need 5,000-10,000 IU of vitamin D daily to replenish tissue stores.* Other individuals who may need higher doses of vitamin D include the obese (the more a person weighs, the greater their vitamin D requirements), individuals with chronic disease, darker-skinned populations, and those with fat malabsorption.* With these individuals specifically in mind, Thorne Research's D-10,000 supplies 10,000 IU of vitamin D3 in each vegetarian capsule.

Some vitamins, because of their potency, are usually given in very small amounts. Examples of such "micro-dose" vitamins include vitamin D, vitamin K, and vitamin B12. Most dietary supplement manufacturers purchase "micro-dose" vitamins from raw material suppliers as premixed dilutions, meaning the vitamins (in powder form) are mixed with other powdered substances that in turn make it easier for the manufacturer to handle and mix a larger quantity of raw material. Unfortunately, the powdered substances used in these premixed dilutions frequently contain potentially detrimental ingredients such as lactose and also the preservatives BHT, BHA, sodium benzoate, and sorbic acid.

At Thorne Research, our promise is to give you the purest supplements humanly possible. Therefore, we do not purchase premixed dilutions of any "micro-dose" vitamins. Instead, we purchase undiluted vitamins and create our own dilutions when it is necessary to do so, using hypoallergenic powders, such as magnesium citrate or plant cellulose. The resultant premixture is then added to the dietary supplement being made, ensuring the proper amount of each nutrient is contained in each capsule.