Did You Take Your “Sunshine Vitamin”?
My daughter and I just had a wonderful time in our backyard pool. Other than the cool water on a hot, summer day, our bodies were able to synthesize vitamin D.
Synthesis of Vitamin D:
Human skin has the unique capability to absorb the sun’s UVB rays and generate vitamin D from cholesterol, hence the nickname “the sunshine vitamin.” UVB rays are strongest near the equator and get weaker as they reach higher altitudes like Europe and America. Variables such as season (fall and winter), time of day, pigmentation (dark skin), amount of skin exposed, and sunscreen impede synthesis, leading to a deficiency of vitamin D in most Britons.
Sources of Vitamin D:
The sun is your free source of vitamin D, and it is able to synthesize just enough for your body. Other sources include fortified food products and supplements. Fatty fish such as salmon and tuna are good sources of vitamin D, but there are not many foods that are naturally rich in it.
There are two forms of vitamin D that are used in supplements: Vitamin D2 (ergocalciferol) which is a pre-vitamin and vitamin D3 (cholecalciferol), the latter of which is similar to the one produced by sunlight and best absorbed by the body.
Vitamin D in Health and Disease:
- Bone health and osteoporosis: Vitamin D is responsible for the absorption of phosphorus and calcium that is required for bone formation and maintenance. Vitamin D deficiency increases the risk of osteoporosis and associated fractures. Vitamin D supplementation, at a high enough dose along with calcium, increases mineral bone density and decreases overall fractures.
- Rickets: Rickets (in children or osteomalacia in adults) is a serious disorder that is associated with severe vitamin D deficiency and prevents the mineralization of bones. Rickets was thought to be a disease of the past, but it has made a resurgence in the last few years, even in industrialized cities. Some of the symptoms in children include the bowing of legs, wider-than-normal hips, and dental abnormalities. Rickets can be alleviated by vitamin D supplementation along with calcium.
- Multiple Sclerosis (MS): MS is an autoimmune, neurodegenerative disease. The T-cells (a type of immune cells) attack the nervous system, causing disabilities. Studies have shown that people who live at higher altitudes have a higher risk of developing MS, suggesting a correlation between geographic location and vitamin D levels. Vitamin D also plays a role in the growth and differentiation of various immune cells of the body. White men and women with higher vitamin D levels have a 62 percent lower risk of developing MS.
- Cardiovascular disease: Vitamin D receptors have been found on the heart and may play a role in controlling blood pressure as well as preventing artery calcification and other cardiovascular diseases. A 20-year study confirmed that men with low vitamin D levels were twice as likely to have a heart attack as those with adequate levels.
- Diabetes: Vitamin D supplementation during infancy reduced the risk of developing Type 1 diabetes by 90 percent compared to those who didn’t receive supplements. Animal and human studies have confirmed the role of vitamin D in glucose metabolism in both Type 1 and Type 2 diabetes. Metabolic syndrome, which is common in today’s generation, was higher in individuals who had low vitamin D and calcium levels.
- Cancer: Nearly 30 years ago, researchers noticed that higher altitudes had a higher rate of colon cancer deaths. Low vitamin D levels increase the risk of developing colon and other cancers, but the evidence is strongest for colon cancer. Vitamin D is able to regulate cell growth and differentiation beneficial for cancer prevention. More studies need to be conducted to confirm the precise relationship between vitamin D and cancer. Currently, the VITAL trial is looking at whether vitamin D can lower cancer risk.
In 2012, the chief medical officers for the United Kingdom issued the following recommendation for appropriate vitamin D dosing:
- Pregnant and breast-feeding women: 10 micrograms of vitamin D daily
- Children ages 6 months to 5 years: Vitamin D drops
- Individuals 65 years old and older: 10 micrograms daily
Research throughout the years has shown that 25 micrograms or 1000 IU is the best dose of vitamin D to get the most health benefits. The maximum suggested limit is around 4000 IU. As always, talk to your physician if you change your supplement routine and stop taking supplements if you observe any discomfort or worsening of symptoms.
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- Catherine Murari-Kanti