What is a good source of ergocalciferol?

January 9, 2026 •

3 min read

Over 50% of the world's population may have insufficient vitamin D levels, highlighting the importance of understanding dietary sources. For those following a plant-based diet or seeking non-animal sources, ergocalciferol is the primary form to consider, making it crucial to know which foods and products provide it.

Quick Summary

Ergocalciferol (Vitamin D2) is primarily found in plant-based sources like UV-exposed mushrooms and fortified foods such as cereals and plant-based milks. Supplements are also a common way to increase ergocalciferol intake, especially for those with dietary restrictions or deficiencies. It helps the body absorb calcium and supports overall bone and immune health.

Key Points

UV-Treated Mushrooms are a top natural source: Fungi like crimini and portabella, when exposed to ultraviolet light, produce significant amounts of ergocalciferol.
Fortified foods provide consistent intake: Plant-based milks, cereals, and orange juice are reliably fortified with ergocalciferol, offering a simple dietary source.
Supplements offer a reliable alternative: For those with a diagnosed deficiency or dietary restrictions, ergocalciferol supplements are a widely available and effective option.
Ergocalciferol is plant-derived vitamin D: It is the primary form for vegans and vegetarians, differentiating it from the animal-sourced cholecalciferol (D3).
Consult a healthcare professional for guidance: The choice between D2 and D3, as well as the appropriate dosage, should be discussed with a doctor, especially for treating deficiencies.
Sunlight exposure boosts mushroom's vitamin D: An easy at-home method to increase ergocalciferol content in mushrooms is to place them gill-side up in direct sun.

Understanding Ergocalciferol (Vitamin D2)

Ergocalciferol, also known as Vitamin D2, is one of the two main forms of vitamin D, alongside cholecalciferol (Vitamin D3). While the body can produce Vitamin D3 from sun exposure, ergocalciferol is derived from plant and fungal sources. This makes it a key vitamin for vegetarians and vegans who may not consume animal products, the main source of D3 in foods. Vitamin D plays a crucial role in regulating calcium and phosphate levels, which are essential for maintaining strong bones and teeth. It also supports immune function, muscle movement, and nervous system health.

Natural Food Sources of Ergocalciferol

Unlike Vitamin D3, which is found in fatty fish, ergocalciferol is less common in nature, with one notable exception: mushrooms.

UV-Treated Mushrooms

Mushrooms are the only significant natural, non-animal source of vitamin D. However, commercially grown mushrooms are often cultivated in the dark, yielding minimal vitamin D content. The key is to find mushrooms that have been exposed to ultraviolet (UV) light, which prompts them to produce vitamin D2 in the same way our skin produces D3 in sunlight.

UV-treated Varieties: Look for product labels explicitly stating that the mushrooms were exposed to UV light. Crimini, portabella, and shiitake are commonly treated varieties.
DIY Sunlight Exposure: You can increase the ergocalciferol content of your own mushrooms by placing them in direct sunlight for a short period. Simply lay them gill-side up for about an hour.

Yeast

Yeast is another fungal source of ergocalciferol, and fortified yeast can be found in some health food products.

Fortified Foods as a Source

Because few foods naturally contain significant levels of vitamin D, many manufacturers fortify products to help people meet their daily requirements. This is a reliable source of ergocalciferol, particularly for those on plant-based diets.

Common Fortified Products:

Plant-based milks: Many varieties of soy, almond, oat, and rice milk are fortified with vitamin D2. Checking the label is essential, as fortification levels can vary between brands.
Breakfast cereals: Most ready-to-eat cereals are fortified with vitamin D and other nutrients. This can be a simple way to start your day with a boost.
Orange juice: Fortified orange juice offers another way to consume ergocalciferol.
Margarine and some yogurts: Some dairy and non-dairy yogurts and margarines are also fortified with vitamin D.

Ergocalciferol Supplements

For those who cannot get sufficient vitamin D from their diet, supplements are a common solution. Ergocalciferol is widely available in various forms, including capsules, tablets, and liquids.

Prescription vs. Over-the-Counter

Depending on the dosage, ergocalciferol supplements are available both over-the-counter and with a doctor's prescription. Prescription-strength supplements are often used to treat specific conditions related to severe vitamin D deficiency, such as rickets and hypoparathyroidism. Always consult a healthcare provider before starting a supplement to determine the right dosage for your needs.

Ergocalciferol vs. Cholecalciferol (D2 vs. D3)

While both forms of vitamin D effectively raise blood levels, some studies suggest that D3 may be more potent and raise levels higher for longer. However, the difference may not be significant for everyone, and both are viable options for treating deficiency.

Comparison Table: Ergocalciferol (D2) vs. Cholecalciferol (D3)


Feature	Ergocalciferol (D2)	Cholecalciferol (D3)
Primary Source	Plants and fungi (e.g., mushrooms)	Animal-sourced foods (e.g., fatty fish, eggs) and human skin
Effectiveness	Effectively raises blood vitamin D levels, though some studies suggest slightly lower efficacy than D3	Often considered more effective at raising and sustaining blood vitamin D levels
Common Forms	Supplements derived from yeast and fortified plant-based foods	Supplements often derived from sheep's lanolin, also found in cod liver oil
Dietary Relevance	Essential for vegans and vegetarians reliant on non-animal sources	Preferred by many due to potentially higher potency, but less suitable for strict vegans

Conclusion

A good source of ergocalciferol depends largely on dietary preferences and personal health needs. For those following a plant-based lifestyle, UV-treated mushrooms are a key natural source, while a variety of fortified foods like plant-based milks and cereals provide reliable dietary intake. Supplements are an effective and widely available option for ensuring adequate vitamin D levels, especially in cases of diagnosed deficiency. Consulting with a healthcare professional can help you determine the best approach to meeting your individual vitamin D needs, considering the relative effectiveness of ergocalciferol (D2) versus cholecalciferol (D3).

Frequently Asked Questions

The primary natural food source of ergocalciferol (Vitamin D2) is mushrooms, particularly those that have been exposed to ultraviolet (UV) light.

No, not all mushrooms contain significant amounts of ergocalciferol. Only mushrooms exposed to UV light, either naturally or artificially, produce high levels of Vitamin D2.

Yes, many foods are fortified with ergocalciferol. Common examples include plant-based milks (soy, almond, oat), orange juice, cereals, and some margarines.

You can check the nutrition facts label on the food packaging. It will typically list the vitamin D content and may specify if it is fortified.

No, ergocalciferol (D2) and cholecalciferol (D3) are two different forms of vitamin D. D2 comes from plant sources, while D3 is primarily from animal sources and skin synthesis.

Yes, ergocalciferol supplements are effective for treating and preventing vitamin D deficiency. Some studies suggest D3 may be slightly more potent, but both are useful.

Those following a vegan or vegetarian diet, as ergocalciferol is the plant-based form of vitamin D. Individuals with dietary restrictions or specific medical conditions may also be prescribed ergocalciferol supplements.