by Meenakshi Bhattacharjee,
The “sunshine” vitamin is a hot topic these days. You may have recently found out that you are deficient or know someone who is. The truth is that a lot has changed, and vitamin D deficiency and insufficiency is now a global public health problem affecting an estimated 1 billion people worldwide.
Vitamin D was discovered to be essential when it was found to be needed for the treatment of rickets. Vitamin D is one of the four fat-soluble vitamins (A, D, E, and K). There are two forms of vitamin D: D2 and D3. Vitamin D2, also known as ergocalciferol, comes from fortified foods, plant foods, and supplements. Vitamin D3, also known as cholecalciferol, comes from fortified foods, animal foods (fatty fish, cod liver oil, eggs, and liver), supplements, and can be made internally when your skin is exposed to ultraviolet (UV) radiation from the sun. Structurally, these two are not the same. Many believe that vitamin D should be classified as a hormone, with some calling it the forgotten neurosteroid. The health consequences of being deficient go far beyond rickets and what occurs with any other vitamin. And unlike other vitamins, it can be made by your body when exposed to sun and the active form in your body, called calcitrol, has similarities to other hormones (estrogen, cortisol, and testosterone).Only 20% of our vitamin D is meant to come from our diet with the remaining 80% provided by our skin from UV-B exposure to the sun.
What are health risks 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-1600’s in children living in industrialized cities in Great Britain with 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 and risks associated with deficiency have been reported. These include the following:
• Type 1 Diabetes: Research has shown that children with type 1 diabetes have a higher chance of having a vitamin D deficiency compared with the general population.
• Multiple sclerosis (MS): Current evidence supports that vitamin D deficiency increases the risk of developing MS and alters the disease activity in people with MS. Numerous studies have linked the occurrence of MS with birth month. There is also a higher prevalence of MS in geographic areas farther from the equator, where people are exposed to less sunlight. The lack of sunlight exposure appears to be a significant predictor, and research is ongoing in this area. A large review of studies shows that with adequate vitamin D levels in people with MS there are fewer relapses, lower risk of development of new lesions in the brain, less disability and disease severity, and better nonverbal long term memory performance.
• Lupus: People with lupus are often photosensitive, causing rashes and possible disease flares when exposed to sunlight. The resulting lack of exposure to sunlight puts them at high risk for vitamin D deficiency. Evidence has shown that a deficiency can affect disease activity and damage along with contributing to the morbidity and mortality in people with systemic lupus erythematosus (SLE).
• Rheumatoid arthritis (RA): A review of research found that people with the highest vitamin D levels had a 24.2% lower risk of developing RA compared to those with the lowest levels. They also found that there was a higher rate of vitamin D deficiency among people with RA than with the general population, and the activity of RA got worse as the level decreased.
to be continued