Make Your Own Vitamin D Supplements for Pennies

Dr. Eric Berg 02/23/2025

Many people wonder about natural ways to boost their vitamin D. A fascinating method is to make vitamin D mushrooms. It's easier than you think to create your own vitamin D-rich mushrooms at home.

This involves using ultraviolet light. Using mushrooms to make vitamin D supplements might sound complex, but this guide walks you through each step.

How to Make Vitamin D Mushrooms

Mushrooms are usually grown in dim environments. They have low levels of vitamin D unless you expose the mushroom to ultraviolet light. Humans also make the vitamin with light exposure.

Research suggests that using this method significantly boosts vitamin levels. Mushroom's vitamin D levels go from 5,000 international units to over 46,000.

Oyster mushrooms, shiitake mushrooms, maitake, or white button mushrooms are usable for this process.

When studies subjected fresh mushrooms to light, the biggest change happened by exposing the gills to the ultraviolet source. White button mushrooms lack gills.

We slice them lengthwise, creating an effect similar to having gills.

Vitamin D illustration

The Type of Vitamin D in Mushrooms

The type of vitamin D that mushrooms exposed to UV light have is D2. It has lower bioavailability. This form of vitamin D doesn’t stay in the system as long as D3 does.

You boost levels so much that it makes up for a shorter lifespan. Combining your enhanced mushrooms with a source of fat improves vitamin D absorption. Consider lightly frying them in butter.

Mushroom's Nutritional Power

These fungi aren't just about vitamin D; they're nutritional powerhouses. With B vitamins, selenium, zinc, and copper, they offer a wide range of micronutrients. Mushrooms provide potassium and other vital components.

Another reason to eat more mushrooms is that they fit into almost any diet. They're even great for low-carb diets like keto. This is due to their low carbohydrate content.

Step-by-Step Guide: Making Vitamin D Mushrooms

Here's how to supercharge mushrooms with vitamin D. First, choose store-bought or foraged mushrooms. The mushroom council notes that you want to look for options in local grocery stores.

Shiitake mushrooms, maitake, and white button mushrooms showed the greatest success. To start, expose your fresh mushrooms to UV light. This UV radiation is essential.

You won’t encounter enough sunlight exposure to work in colder months. Latitude is a major factor. Try this in months with intense sunlight, like July or August.

But a UV lamp works no matter the month. If it's summer, place your mushroom gill side up on a cooking sheet. Remove the stems before exposing them.

Exposure To Light

The stem area doesn’t convert much vitamin D, so remove them. If using white button mushrooms, place the cut side up. Direct sun exposure will work.

Start around 10:00 AM and go until about 6:00 PM the first day. Bring the mushrooms exposed to the sun in before moisture condenses. Give your mushrooms a second round of UV rays on day two.

Do the same as day one and dry the mushroom completely. This gives a long-lasting result.

To check for dampness, bend one in half. It should crack easily. Place them in an airtight container to prevent degradation.

This also preserves them longer. If there's moisture, add something that absorbs moisture. A desiccant packet can help with this.

Don't expose them to sunlight for more than two days. Studies show that vitamin D levels may then decrease. If you don't have access to summer sunlight, buy a UV bulb.

One cup of transformed shiitake (about 100g) equals about 46,000 IUs of vitamin D. Exposing shiitake mushrooms to artificial UV B rays for 18 hours results in over 200,000 IUs.

The American Journal of Clinical Nutrition has also published papers regarding the increase in serum concentrations after ingesting irradiated mushrooms.

White button varieties see a 20,000 IU lift. Raw, non-dried varieties need less UV B exposure, sometimes reaching 600 - 5,000 IUs in 15 to 120 minutes.

There was also a six-fold increase when exposed to continuous UVB light compared to normal mushrooms.

vitamin D pill with a spoon

Tips and Precautions

Mushrooms vary in quality. Discard any that smell off or change color. The fact sheet put out regarding dietary supplements also suggests this.

Only use fresh, healthy-looking types. Don’t take risks. Store them properly. Use airtight, sealed containers. Improper storage causes rapid degradation.

Excess moisture and temperature changes hurt vitamin D levels. Keep them in a cool, stable environment.

According to Heaney RP and Recker RR, dietary reference intakes should be considered when trying to figure out appropriate serum levels that would be considered adequate vitamin D levels.

Optimizing Mushroom Intake

Include fatty elements with cooked mushrooms for vitamin D absorption. Don't take excessive vitamin D. Combine intermittent fasting and balanced nutrition for the best results.

Mushroom growers are working to find new ways for mushrooms to generate vitamin D. Research suggests that if you have darker skin, you might require a higher recommended daily amount to avoid a deficiency.

This would especially be important during times when getting out in the midday sun is more difficult.

Over a billion people worldwide are considered deficient, which could impact bone health and potentially even increase cancer risk.

Always seek professional medical advice from sources like the Holick MF if trying to address deficiencies in healthy adults or find more natural vitamin D.

If unable to consume mushrooms for some reason, there are supplemental vitamin D options.

Balancing Essential Nutrients for Optimal Vitamin D Absorption

Mushroom-derived vitamin D supplements provide a plant-based alternative to traditional sources, helping support immune function, bone health, and overall well-being.

However, maintaining the right nutrient balance is crucial for proper absorption and preventing imbalances that could negatively affect health.

For instance, individuals concerned about copper toxicity IUD exposure may need to pay extra attention to their mineral intake, as excessive copper can interfere with zinc levels, which are essential for vitamin D metabolism.

Ensuring adequate zinc intake through whole foods like grass-fed meats, nuts, and seeds can help counteract potential mineral imbalances while enhancing the benefits of vitamin D supplementation.

Pairing these dietary choices with intermittent fasting and a nutrient-dense keto lifestyle supports optimal absorption and long-term wellness, allowing the body to maintain hormonal and mineral equilibrium.

Conclusion

Boosting vitamin D with food is a constant goal for health. Vitamin D mushrooms offer great ways to add minerals. Making your vitamin D-enriched mushrooms using these methods provides nutritional value.

Exposing fungi to sunlight for a few hours increases vitamin D production by thousands of units.

Consuming mushrooms that have higher levels can impact things like serum vitamin D levels in the body. Learning about this improves well-being.

Start your journey now. Use these insights on making more nutritionally balanced fungi and to better understand how to make vitamin D mushrooms.

There is plenty of clinical data in sources like Google Scholar; should more specific numbers on things like IU be needed?

FAQs about making Vitamin D Mushrooms

How to make vitamin D mushrooms?

Place mushroom gills towards the sun or use UV light. For white button mushrooms, slice and arrange them lengthwise. Remove stems, as they don't help.

What mushrooms are high in vitamin D?

All varieties exposed to UV radiation have increased vitamin D. Shiitake mushrooms, oyster mushrooms, maitake, and white button fungi all provide large IU boosts. Levels depend on sunlight and UV light contact time.

Brown mushrooms often have higher levels than white mushrooms, even before UV exposure.

How many mushrooms a day for vitamin D?

One cup of UV-exposed, dried mushrooms creates over 40,000 IUs of vitamin D. With such high results, small portions will likely have beneficial effects. Consider that in your dietary reference intakes.

Even just putting your fresh button mushrooms in the sun will increase vitamin D.