Hypoallergenic, Gluten and Casein Free. Capsules are plant based. Ultra Tested®. Vitamin D has many roles in the body. This nutrient is needed for bone growth and maintenance.* Strong evidence suggests that it supports calcium absorption, modulates cell growth and supports neuromuscular and immune system function.* Scientists are discovering that inadequate vitamin D is a widespread problem. As a result, there have been several recent increases in the recommended daily intake of vitamin D. In 2008, the American Academy of Pediatrics updated guidelines for vitamin D daily intake for infants 0-1 year old and children and adolescents from 200 IU to 400 IU. In 2010, the Institute of Medicine set new recommended daily allowances for those 1-70 years of age at 600 IUs; for those 71 years and older, 800 IUs; and for pregnant and lactating women, 600 IUs. Relatively few foods naturally contain vitamin D. It is best obtained from sunshine; however, the use of sunscreen can limit the amount of vitamin D absorbed from the sun. People living in cloudy or rainy climates are also often prone to low vitamin D levels. Certain cod liver oils can also be a good source of vitamin D. Vitamin D levels fluctuate in the body due to many factors. Laboratory tests can be done to establish a baseline level that physicians may use to suggest adequate supplementation.