We get many vitamins from foods we eat, but none is quite like vitamin D. Nicknamed the “sunshine vitamin,” we obtain it best through exposure to sunlight. With between 80 to 90 percent of our vitamin D intake coming from the sun, knowing just how much sunlight we need to expose ourselves to — and how much sunlight is safe — can be a challenge. Here’s everything you need to know about vitamin D.
What makes vitamin D different?
Of all the nutrients we get on a daily basis, vitamin D is different for many reasons, not the least of which is its status as a prohormone. If you’ve never heard the term before, a prohormone is a fat-soluble substance that, on its own, isn’t very active. But when vitamin D enters the body via sunlight, it turns into a hormone. Because it is fat-soluble, vitamin D dissolves in fat. Our bodies store it for quite some time, so the sunshine we get today can go on helping us tomorrow and beyond.
Biologically inert, vitamin D must be processed in a couple of different regions of the body to become something useful. After a bit of time in the sun, two types of vitamin D are produced. The first type is calcidiol, or vitamin D2, which is processed in the liver. The second type becomes activated in the kidneys and is known as calcitriol, or vitamin D3.
Vitamin D2 is stored within our bodies, while vitamin D3 is the active form of the vitamin that immediately impacts our health. Together these forms of vitamin D offer a wealth of benefits that are essential to our wellness.
Vitamin D’s role in our bodies
Vitamin D is significant in terms of our bone health. The sunshine vitamin enables our bodies to absorb calcium to allow for bone mineralization. This process helps harden our bones, keeping them from becoming brittle.
Adequate vitamin D intake prevents and treats rickets, a disease in children that is identified by the improper calcification or malformation of bones. Rickets typically presents itself in the lower part of the body, specifically the legs. The sunshine vitamin is also used to treat a variety of conditions, including osteoporosis, bone pain (osteomalacia), bone loss in patients with hyperparathyroidism, kidney failure and the skeletal genetic disease, osteogenesis imperfecta.
Other benefits of vitamin D include the reduction of inflammation in the body, as well as support for our neuromuscular function (the interaction between nerves and muscles) and a healthy immune system. According to the Harvard School of Public Health, adequate levels of vitamin D even promote heart health and reduce the likelihood of heart attack, stroke or other cardiovascular diseases.
According to a study published in the International Journal of Epidemiology, there’s also evidence that adequate sunlight and vitamin D reduce the likelihood of developing colon cancer. Observational studies published in the Annals of Epidemiology suggest that incidences of breast cancer, as well death caused by breast and colorectal cancer, could be greatly reduced with proper exposure to vitamin D.
Food sources
There are a few food sources that give us vitamin D, but the best source is the sun. That said, eating foods that contain vitamin D can’t hurt. Fatty fish such as tuna, sardines, mackerel and herring contain a good amount of this vitamin, and many people regularly supplement their diet with cod liver oil for this same reason. Other foods that have a small amount of vitamin D include beef liver, cheese, egg yolks and certain types of mushrooms. But the best way to ensure your body has sufficient vitamin D is to catch some rays.
The safe way to get vitamin D from the sun
The conflict between needing to acquire vitamin D from the sun and concerns about overexposure to cancer-causing amounts of UV rays leads some people to shy away from the sun. The good news is that it doesn’t take long for our bodies to absorb enough sunlight to give us the vitamin D boost we need. We certainly don’t have to get a sunburn to get enough Vitamin D.
A good rule of thumb is to expose your bare skin for about half the time it takes for you to begin to get pink. Exposure time varies from person to person, and fair-skinned people will need much less time in the sun than those with darker pigmentation. Start with about 15 minutes of sun exposure two to three times a week to give your body a boost of nourishing vitamin D. Adjust your time outdoors as you see fit, but remember, avoid sunburns to reduce aging or potentially cancer-causing effects.
When deciding to get out into the sun, another factor to be aware of is your geographic location. According to the Harvard School of Public Health, people who live north of the line that runs through San Francisco, Philadelphia, Athens and Beijing probably don’t get enough vitamin D. In fact, there are about one billion people globally who don’t get enough of the sunshine vitamin, and deficiencies are the result. If you live in South Dakota, you’ll probably need to get out in the sun more than if you live in South Florida.
So get outside and soak up some sun today — it’s good for your health. To help others think of fun ways to get some rays, tell us your favorite outdoor activity.
—The Alternative Daily
Sources:
https://ods.od.nih.gov/factsheets/VitaminD-HealthProfessional
http://www.cancer.gov/about-cancer/causes-prevention/risk/diet/vitamin-d-fact-sheet
http://lpi.oregonstate.edu/mic/vitamins/vitamin-D
http://www.hsph.harvard.edu/nutritionsource/vitamin-d
https://www.vitamindcouncil.org/about-vitamin-d/how-do-i-get-the-vitamin-d-my-body-needs
http://www.ncbi.nlm.nih.gov/pubmed/19523595?dopt=Citation
http://www.ncbi.nlm.nih.gov/pubmed/7440046?dopt=Citation
