You + Sun = Vitamin D!

Thursday, August 4, 2011

Summer’s here, and it’s time for fun in the sun! And while you’re lounging by the pool, strolling on the beach, or entertaining in the backyard, you’re not just enjoying the summer sun — you’re making oh-so-essential vitamin D, too! Vitamin D helps our bodies absorb calcium, which is essential for bone growth and bone density maintenance. Without sufficient vitamin D, bones can become thin or brittle, potentially leading to disorders such as rickets, osteomalacia, and osteoporosis. Vitamin D also affects neuromuscular and immune functions, reduces inflammation, and influences genes that regulate cell proliferation, differentiation, and apoptosis. Given vitamin D’s importance in the body, it’s understandable that our bodies are capable of synthesizing it. So how does this happen?

The type of vitamin D that our bodies make is D3 (cholecalciferol), and its production, occurs in the epidermis of the skin when 7-dehydrocholesterol (a cholesterol precursor) reacts with ultraviolet light (UVB) at wavelengths between 270 and 300 nm. To perform its functions, cholecalciferol must be converted to its active forms. After synthesis in the skin, cholecalciferol enters the blood and is transported to the liver, where it is hydroxylated to form 25-hydroxyvitamin D (calcidiol). A second hydroxylation reaction occurs in the kidney, resulting in the formation of 1,25-dihydroxyvitamin D (calcitriol). While calcidiol is the major form of vitamin D in the blood and is the form measured to assess nutritional status, calcitriol is responsible for most of vitamin D’s functions in the body.

Sunlight exposure may not provide enough vitamin D for everyone. People with dark-colored skin and the elderly synthesize less vitamin D with sunlight exposure. And, as you might expect, people who do not live in sunny areas year-round may not make enough vitamin D to meet their nutritional requirements. Cloudy days, shade, and protective clothing reduce the amount of vitamin D the skin makes. Even the application of sunscreen with SPF 8 reduces production of vitamin D by 95%! This does not mean that you should avoid wearing sunscreen. Experts recommend 10 to 15 minutes of direct sunshine three times weekly; after that amount of time you should apply sunscreen to prevent skin cancer and sun damage.

So go outside and get your 10-15 minutes of vitamin D! But don’t forget the sunscreen!


Karen Brothers, ND student, NCNM

For more information about vitamin D::
National Institutes of Health, Office of Dietary Supplements
Micronutrient Information Center, Linus Pauling Institute at Oregon State University

Labels: cancer prevention, D vitamins, D3, health benefits, sun, sunblock, sunlight, vitamin D

posted by Innate Response at

10:10 AM

2 Comments :

HealthTourism said...: oh really...This is very informative and helpful for all..Thank you so much for sharing..:)

Regards,
Amilya
Healthcare Jobs; January 17, 2012 at 1:36 AM
Anonymous said...: You are doing great work keep it up!!!

Regards
http://www.allmedexams.com; January 17, 2012 at 7:30 AM

You + Sun = Vitamin D!

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