Why do i have vitamin d deficiency if i'm taking multivitamins daily?

Vitamin D: Many Americans increasingly have a vitamin D deficiency. Simply taking a multi Vitamin probably does not provide enough vitamin D for adequate supplementation to our diets. Vitamin D is actually a hormone and plays a vital role in our health. Consider taking a specific and vitamin D supplement in consultation with your dr. Vitamin D levels must be monitored. Too much or too low are both bad