1. Amazing Vitamin D Slideshow Pictures
2. Take the Vitamins Quiz

Author:

Betty Kovacs, MS, RD

Betty Kovacs, MS, RD

Betty is a Registered Dietitian who earned her B.S. degree in Food and Nutrition from Marymount College of Fordham University and her M.S. degree in Clinical Nutrition from New York University. She is the Co-Director and Director of nutrition for the New York Obesity Research Center Weight Loss Program.

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Medical Editor:

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD

Melissa Conrad Stöppler, MD, is a U.S. board-certified Anatomic Pathologist with subspecialty training in the fields of Experimental and Molecular Pathology. Dr. Stöppler's educational background includes a BA with Highest Distinction from the University of Virginia and an MD from the University of North Carolina. She completed residency training in Anatomic Pathology at Georgetown University followed by subspecialty fellowship training in molecular diagnostics and experimental pathology.

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In this Article

• What is vitamin D?
• What does vitamin D do for one's health? What are symptoms and signs of vitamin D deficiency?
• What causes a vitamin D deficiency?
• How is a vitamin D deficiency diagnosed?
• What is the treatment for a vitamin D deficiency?
• Can vitamin D deficiency be prevented?
• What are symptoms and signs of an excessive vitamin D intake?
• Vitamin D FAQs
• Patient Comments: Vitamin D Deficiency - Tests
• Patient Comments: Vitamin D Deficiency - Treatment
• Patient Comments: Vitamin D Deficiency - Symptoms
• Find a local Doctor in your town
• Vitamin D Deficiency Index

By the turn of the 20th century, 90% of the children living in New York, Boston, and Leyden in the Netherlands were afflicted with rickets, a bone-deforming disease. The first observation of this disease was in the mid-1600s by Whistler and Glissen, who reported that children living in industrialized cities in Great Britain had short stature and deformities of the skeleton, especially of the lower legs. It wasn't until 1889 that the discovery that "sunbathing" was important for preventing rickets came about.

The need for vitamin D goes way beyond preventing and treating rickets. Various researchers have claimed that vitamin D benefits are associated with the following:

• Prevention of osteoporosis and osteopenia
• Lowering blood pressure in people with hypertension
• Lowering incidence and severity of cardiovascular disorders
• Decreasing the incidence of type 2 diabetes: Research has shown that those with blood vitamin D levels over 25 ng/mL had a 43% reduced risk of developing type 2 diabetes compared with those with levels under 14 ng/mL.
• Decreasing inflammation: Research has shown a decrease in levels of C-reactive protein, a marker of inflammation, with increased levels of vitamin D to just below 21 ng/mL.
• Reducing risk of allergies in children and adolescents: A nationwide study of over 6,000 individuals showed that allergic sensitization was more common in those with vitamin D levels under 15 ng/mL versus those with levels 30 ng/mL or more.
• Decreasing dental cavities: A 47% reduced risk of cavities was found with vitamin D supplementation.
• Prevention and treatment of depression: Receptors for vitamin D are present on many areas of the brain including the cingulate cortex and hippocampus, which have been implicated in the pathophysiology of depression. Vitamin D is involved in numerous brain processes, making it biologically likely that this vitamin might be associated with depression and that its supplementation might play an important part in the treatment of depression.
• Possibly helping with erectile dysfunction (ED): It is not clear if increasing your serum vitamin D levels can help with ED. Many men diagnosed with ED are diagnosed with cardiovascular disease (CVD) within a few years. Vitamin D deficiency is linked with CVD, so if you are deficient in vitamin D, some researchers believe that treating this could reduce your risk of CVD and then possibly ED.
• Regulating cholesterol levels in the blood: It has been shown that without adequate sun exposure, vitamin D precursors turn to cholesterol instead of vitamin D.
• Decreasing mortality rate from certain cancers: In 1941, U.S. pathologist Frank Apperly published geographic data that demonstrated for the first time an inverse correlation between levels of UV radiation in North America and mortality rates from cancers. This means that more exposure to UV radiation (sun) leads to fewer deaths from cancers. In the meantime, since this was published, it has been confirmed that there is an association between increased risk of dying of various internal malignancies (for example, colon, breast, ovarian, melanoma, and prostate cancer) and decreasing latitude toward the equator.
• Decreasing risk of osteoarthritis: Vitamin D deficiency may increase the risk of osteoarthritis.
• Possibly helpful in prevention of fractures, improving balance, and reducing the risk of falls in the elderly: There has been some evidence suggesting that vitamin D supplementation may have these benefits, but more research needs to be done to confirm it.
• More research is needed to determine the possible benefit of vitamin D as therapy for multiple sclerosis, tuberculosis, influenza, and viral upper respiratory tract illnesses.