The majority of Americans (both children and adults) are deficient in vitamin D. Vitamin D deficiency is associated with numerous diseases, such as cardiovascular disease, hypertension, stroke, diabetes, multiple sclerosis, rheumatoid arthritis, inflammatory bowel disease, depression, osteoporosis, psoriasis, periodontal disease, macular degeneration, mental illness, propensity to fall, and chronic pain.
Beyond its role in enhancing calcium absorption, new research has shown that vitamin D improves immune function (fights colds and flus) and can reduce the risk of a variety of cancers.
Factors that affect vitamin D status include: latitude, season, time of day, air pollution, cloud cover, melanin content of the skin, use of sunblock, age, and the extent of clothing covering the body. Also, prescription medications can deplete vitamin D levels.
Beyond daily full body, midday sun exposure for 10-15 minutes, the treatment of choice for vitamin D deficiency is supplementing with vitamin D3. Unfortunately, foods are not great sources of vitamin D.
Vitamin D3 (cholecalciferol) is the preferred, active form of vitamin D. Vitamin D2 (ergocalciferol) is what is commonly prescribed by doctors and found in some lower quality vitamin formulas. Safe and effective recommendations for vitamin D3 supplementation are 1,000 to 2000 IU/daily, and higher. Optimal vitamin D levels are well above 40 ng/mL. Ask your doctor to test for 25-hydroxy vitamin D to determine your levels. If you are below 40 ng/ml, you may want to discuss a higher dosage with your doctor.