Vitamin D Deficiency

What does vitamin D do for your health? What are symptoms and signs of vitamin D deficiency?

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.

Since then, many other health benefits of vitamin D have been discovered. These include the following:

Skeletal disease: Anyone taking calcium knows that you need to take it with vitamin D. It's needed because vitamin D promotes calcium absorption in the gut and maintains blood calcium levels to enable normal mineralization of bone and prevent abnormally low blood calcium levels that can then lead to tetany. Adequate vitamin D levels can prevent bones from becoming thin, brittle, or malformed. It is linked with the prevention of osteomalacia, osteopenia, and osteoporosis.

Fall prevention is a public-health goal for the elderly. Each year, one in three people 65 years and older experiences at least one fall, with 5.6% resulting in a fracture, and vitamin D can play a role in preventing this. There are vitamin D receptors in human muscle that have a direct effect on muscle strength. A severe vitamin D deficiency can cause myopathy, which can cause muscle weakness and pain. Vitamin D supplementation can reverse this and improve balance. Supplementing 700 to 1,000 IU/day of vitamin D3 has been shown to reduce falls by 19%-26%.

Another advantage to correcting a vitamin D deficiency has been seen in decreasing knee and hip pain. A longitudinal population-based cohort study of 769 randomly selected older adults aged 50-80 years found that moderate vitamin D deficiency predicts the incidence or worsening of knee pain over five years and possibly hip pain over 2.4 years.

Cancer: The link between the sun and cancer is typically not seen as a positive one because of the connection with skin cancer. UV-B radiation from the sun is said to be the most important environmental risk factor for nonmelanoma skin cancer. Because the sun is the primary source of vitamin D, researchers are looking to see what role it plays in skin cancer. Some believe that enough sun exposure to keep your vitamin D levels up while protecting your skin from damage is beneficial to skin cancer survival. There has also been research to show the protective effect that vitamin D has with the development of other cancers, including colon, breast, and prostate cancer.

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. Since this was published, it has been confirmed that there is an association between an increased risk of dying of various internal malignancies (for example, colon, breast, ovarian, melanoma, and prostate cancer) and living far from the equator.

Reviewed on 2/26/2015