NOW THAT THE WARMER months are here, it’s a good time to discuss a vitamin that has been getting a lot of press lately: vitamin D, also known as the sunshine vitamin. Ironic, because vitamin D is not a vitamin nor a nutrient; it is a hormone produced by the body in the skin from a photolytic reaction with ultraviolet light.
Many of us live in more northern latitudes, which is pretty much considered north of Florida in the United States, where ample sunlight is not available year round, or we spend the majority of our time indoors—meaning many individuals need to obtain this nutrient from their diet. Therefore, it is considered a vitamin for these particular individuals.
Vitamin D has always received much attention for its critical role in supporting healthy bones and teeth. When I was in school, which was only a decade ago, other “nonclassical functions” of vitamin D were being proposed and studied, such as its roles in immune function, treatment of skin diseases and possible antitumor effects.
Today, our knowledge of the versatility of this hormone has grown significantly, but there are many questions still to be answered. This is one of the reasons why I love the field of nutrition; we are learning new things each day (as well as unlearning things we thought to be true before). How beautiful and humbling the complexity of the human body!
The best animal sources are liver, especially from cod, herring and sardines.
I always prefer to get my nutrition from food whenever possible, but vitamin D presents some obstacles. Food sources are minimal, and this is the major reason why dairy and other food products are fortified with vitamin D.
Some plants contain small amounts of the non-biologically active form of vitamin D, such as fungi-yeast, molds, and mushrooms. The best animal sources are liver, especially from cod, herring and sardines. Hence why so many were forced to gulp these oils down as kids to stay healthy through the winter and why those living in extremely dark climates, have these fish as a staple in the diet. Nature always knows best!
This is one of the many reasons I love summer. I can get my vitamin D from the sun and have one less supplement to take for a few months. Advice from the Vitamin D Council:
“For those who do not fear the sun, judiciously expose as much skin as possible to direct midday sunlight for 1/4 the time it takes for one’s skin to turn red during those months when the proper ultraviolet light occurs at one’s latitude (usually late spring, summer and early fall). Do not get sunburned. Vitamin D production is already maximized before your skin turns pink and further exposure does not increase levels of vitamin D but may increase your risk of skin cancer.”
They also point out that people with dark skin may need 5–10 times longer in the sun than light-skinned people.
Like many things in this young field of nutritional sciences, it is easy to jump on an idea and run with it. We have learned a lot over the past few decades, but also have created much confusion around nutrition advice. Vitamin D is a good example of this. There is still much we don’t know and more vitamin D supplementation is not always better. I feel the following guidelines are good ones to keep in mind:
There are many different “optimal ranges” being recommended from the medical and scientific experts.
- Before starting to supplement with vitamin D, have your 25 OH vitamin D levels checked with your doctor. This will give you and your doctor an idea of how much you may need to supplement.
- Use a product containing vitamin D3, preferable in capsule or drop form. To improve absorption, vitamin D should be taken with food that contains some fat, since it is fat soluble.
- Have your level rechecked every three months. Remember, vitamin D is a hormone, so it fluctuates for everyone differently, and obviously seasonal changes affect it as well.
- There are many different “optimal ranges” being recommended from the medical and scientific experts. As of now, it seems to me, you definitely want it over 30ng/ml and not more than 80ng/ml.
- For those who have chronic infections, autoimmune conditions or have been supplementing and can’t seem to get your 25 OH levels up, it is being advised to also have your 1,25 OH vitamin D levels checked. If this is elevated, you may not necessarily want to supplement. Discuss this further with your doctor if you feel you fit this profile.
In summary, always keep to the basic concepts as much as possible when it comes to nutrition advice. Michael Pollan, I think, summarized it best when he wrote: “Eat food. Not too much. Mostly plants.” (He meant whole food, of course.)
Same with vitamin D: Have your doctor monitor your vitamin D status, if you need it, and take it based on his/her recommendations with dosing. And if you like the sun and can tolerate the heat, get out there and catch some rays. There are many other therapeutic properties to getting some natural sunlight daily, as well. Just don’t forget to cover up after awhile. For me, being of Irish/German/Lithuanian descent, that’s only about 15-20 minutes midday before I can start getting pink!
For more information go to: The Vitamin D Council