Thursday, October 22, 2009

Nature's Hidden Source of Vitamin D

When vitamin D comes to mind, we usually think of sunshine. Sunshine is without a doubt the best source of vitamin D. However, we don’t always have access to it, especially during the winter months, if we live at northern latitudes, or if we spend most of our time indoors. With limited sun exposure, we rely on food for vitamin D. It can be challenging to meet our daily vitamin D needs with food, particularly if we are vegan or vegetarian. Cold water fish, cod liver oil, milk and egg yolks are some foods with high levels of vitamin D3 or cholecalciferol. One would need to consume 4 ounces of fish or 4 cups of milk to meet the daily recommendation of 400 IU.

Another source of vitamin D in our diet is mushrooms. Mushrooms contain a slightly different version of vitamin D called ergocalciferol. Ergocalciferol or vitamin D2 is produced when mushrooms are exposed to UVB light. Mushrooms are usually cultivated indoors, so much of this vitamin D is not produced under these conditions. Recently, mushroom producers have paired with the FDA and academic institutions to study the impact of UV light on vitamin D production in mushrooms. What they’ve discovered is that exposure to UV light during the cultivation process significantly increases the ergocalciferol content of some varieties of mushrooms. Although studies are being conducted to determine whether the biological activity of ergocalciferol is equivalent to that of cholecalciferol, the vitamin D found in animal sources.

Vitamin D plays a critical role in calcium absorption and bone health. Recent studies have linked vitamin D deficiency with osteoporosis, some cancers, cardiovascular disease, and autoimmune illnesses such as multiple sclerosis, rheumatoid arthritis and insulin-dependent diabetes. Those at risk for vitamin D deficiency include older adults, individuals living at northern latitudes, people with dark skin, and those with fat malabsorption. Given its role in promoting health and preventing disease, it's critical that we optimize our vitamin D status. Mushrooms may be one food source of vitamin D and they have other nutritional benefits. They are high in B vitamins, potassium, zinc, phosphorous and selenium. In addition, they are free of cholesterol and fat, and have one of the highest protein contents of any vegetable. The Pacific Northwest offers hundreds of varieties of wild edible mushrooms. You can purchase these at farmer’s markets or at the grocery store and prepare them using a variety of cooking techniques including roasting, stewing, frying and sautéing.


aletheia said...

I really appreciate this post, because you specifically address the sole source of dietary vitamin D for vegans - mushrooms! I've been D-ficient (:P) for a while now, no doubt attributable to my plant-based diet, and even though I take supplements, it's nice to really hear about Nature's Hidden Source of Vitamin D.

On the whole, I really like your blog. I specifically also like how you don't shy away from using studies and findings to support what you are saying. Now that's what I think is a great foodie mind put to great use. ;) Keep it up! Looking forward to following your blog!

Genevieve Sherrow said...

Thank you Aletheia. I try to use scientific research as much as possible to support my writing. I enjoy summarizing data from studies. Thank you for your comments and support.

Sharon Gray said...

Mmmmmm... Informative AND delicious! Thanks, Genevieve! :)