IU means international unit. Its a common unit of measure used around the world. My name is Greg L. and I've been a registered nurse for over 12 years. My passion is educating people on natural ways of healing the human body and prevetion of disease. I use 5000iu of Vitamin D3 every other days to avoid toxicity.
Vitamin D2 and/or Vitamin D3
There are two types of vitamin D supplements available for over-the-counter purchase (vitamin D2 and vitamin D3). Vitamin D3 is the type that most experts believe should be utilized in clinical practice (Wolpowitz & Gilchrest, 2006). Vitamin D2 is also known as "ergocalciferol," and vitamin D3 is also known as "cholecalciferol." This is important for patients who have purchased a dietary supplement that does not indicate the specific type of vitamin D in the product by number but have listed the scientific name. Most experts now believe that the only form that should be purchased is vitamin D3. Vitamin D2 is also very acceptable, but in the author's opinion, most individuals should switch to D3. There is a plethora of logical reasons for advocating the use of vitamin D3 over vitamin D2 dietary supplements (Wolpowitz, & Gilchrest, 2006), including:
UVB light from the sun strikes the skin, and humans synthesize vitamin D3, so it is the most "natural" form. Human beings do not make vitamin D2, and most healthy fish contain vitamin D3.
Vitamin D3 is the same price as vitamin D2.
Vitamin D3 may be less toxic than D2 because higher concentrations of D2 circulate in the blood when consumed (compared to vitamin D3). It does not bind as well to the receptors in the human tissues compared to vitamin D3.
None that I can see, Gary. As I read the label for "fillers," I don't see any corn products listed. I consider NOW products pretty clean and reliable. What you might do is get on the NOW website and/or call them for validation to be sure.
Are you asking if you need to supplement k2 while taking D3? If so, I do acknowledge that k2 is important and needed. Now sure what your situation is, but for a healthy person, most people get adequate k2 from their diet. It's found in eggs, cheeses, beef, etc. Depending on your health, you may want to take a supplement. My son eats a good diet and does not take supplemental k2. At least not right now.