Did you know that vitamin D insufficiency affects almost 50% of the population worldwide? Vitamin D plays a critical role in our health – in fact, vitamin D acts as a hormone by binding to vitamin D receptors present in most tissues and cells in the body. Emerging research supports the possible role of vitamin D against cancer, heart disease, fractures and falls, autoimmune diseases, influenza, type-2 diabetes, and depression.

So if vitamin D plays such an important role in our health, how has vitamin D deficiency become a global public health issue? Research shows that our decreased time in the sun and decreased consumption of vitamin D containing foods may be the primary causes of vitamin D deficiency. We often call vitamin D “the sunshine vitamin” because we activate vitamin D in our skin when we are exposed to the sun’s rays. We also consume vitamin D dietarily in fatty fish, mushrooms (more on this below), and certain fortified foods. Twenty minutes of sunshine daily (at the proper zenith angle) with over 40% of skin exposed or a daily intake of around 600-2,000 IU of vitamin D is required to prevent vitamin D deficiency.
If you are a patient at Natural Medicine of Denver, it is likely we have discussed the importance of maintaining healthy levels of vitamin D and have probably even tested your blood levels to ensure they are in the adequate range – generally we advise our patients to reach a goal of around 60 ng/mL on their 25-hydroxy vitamin D blood test.
This becomes very important to consider as a new peer-reviewed study recently published in PLOS ONE has shown that patients hospitalized for COVID-19 were more likely to develop severe or critical disease if their blood levels of 25-hydroxy vitamin D were less than 20 ng/mL. In fact, patients with vitamin D deficiency were 14 times more likely to have severe or critical COVID-19 disease than patients with 25-hydroxy vitamin D levels above 40 ng/mL.
As mentioned above, sun exposure is only an effective means of vitamin D synthesis when the sun’s rays are at the proper zenith angle. Factors that affect this condition are latitude, season of the year, and time of day. During the fall, winter, and spring months in the Northern Hemisphere it is likely that our ability to make adequate vitamin D is limited by our latitude. For this reason, during these seasons we especially need to focus on our dietary intake of vitamin D first through foods and then with supplementation when needed.

If you are unsure about your vitamin D status, you can reach out to your doctor at Natural Medicine of Denver to schedule a quick blood test. If you have questions about how best to personally address low vitamin D levels, we would be happy to discuss this with you and create an individualized plan.

After the recent release of the above mentioned article relating vitamin D deficiency to COVID-19 severity, we have been on the hunt for all the best approaches for improving our patients’ dietary intake of vitamin D. In our research, we came across some interesting data from mycologist and researcher Paul Stamets who teaches us how to take our everyday mushrooms and exponentially increase their vitamin D content by strategically setting them out in the summer sunshine – the vitamin D levels in these mushrooms soared from 100 IU/100 grams to nearly 46,000 IU/100 grams with the following protocol.
We especially like this dietary option for supporting vitamin D levels because we also know that consuming mushrooms confers many other health benefits. Mushrooms contain high amounts of beta glucans which benefit immune function, antioxidants known as ergothioneines, nerve growth stimulators that help brain function, and antimicrobial compounds for limiting viruses.

Paul Stamets’ Recipe for Vitamin D Enhancement of Mushrooms:

1. Obtain fresh organic shiitake, maitake, button, oyster, shimeji or other mushrooms.
2. On a sunny day in June, July or August, slice the fresh mushrooms. Place them evenly on a tray exposed directly to the sun from 10 am to 4 pm.
3. Before nightfall, cover the mushrooms with a layer of cardboard to block moisture from dewfall.
4. The next clear day repeat exposure to the sun from 10 am to 4 pm.
5. Remove the mushrooms and finish drying (if necessary, in a food dehydrator until they are crispy).
6. When thoroughly dry, store in a glass jar or sealed container. Adding a tablespoon of uncooked rice as a moisture absorber will help keep the mushrooms dry. The mushrooms should be good for a year or more, depending upon conditions.
7. Take 10 grams daily per person, about a small handful. Rehydrate in water for one hour. The mushrooms will swell. Then cook as desired.