Vitamin D plays a crucial role in the body’s absorption of calcium for maintaining bone health. Without enough vitamin D, the bones will soften, leading to rickets in children or osteomalacia in adults. New research suggests that the vitamin may also play a role in immunity and protect against diabetes, high blood pressure, heart disease and certain cancers. Unfortunately, research is also finding that vitamin D deficiencies are estimated to occur in 30-50% of the population, numbers higher across all age groups than previously thought.
The body does produce vitamin D when exposed to sunlight. However, for those living in places with inadequate sunlight (a.k.a Vermont, especially when it is 37 degrees and snowy in the end of April), the body has trouble producing enough vitamin D. For these individuals, it is particularly important to get sufficient vitamin D from the diet. The primary source of vitamin D for Americans is milk. Other sources include whole eggs, fatty fish such as catfish, mackerel and salmon, and fortified foods such as yogurt, breakfast cereals, breads, margarine and oil spreads.
Due in part to the new findings regarding the function of vitamin D and prevalence of deficiencies, recommendations for daily intake are variable. Dosage for vitamin D is measured in International Units (IU) and the best bet appears to be a daily dosage of 400 IU per day for children, or the amount in 4 glasses of milk, and should not exceed 2,000 IU daily. Adults should have 400-800 IU daily without exceeding 10,000 IU.