How can I increase my D2 level? A guide to ergocalciferol sources

October 16, 2025 •

3 min read

According to the National Institutes of Health, adequate vitamin D is crucial for bone and overall health, but many don't get enough. For those relying on plant-based nutrition, understanding how can I increase my D2 level through food and supplements is a key part of maintaining health.

Quick Summary

Increasing vitamin D2 levels involves consuming specific plant-based foods, such as UV-exposed mushrooms, and fortified products like plant-based milks and cereals. Supplements may also be necessary, and proper absorption depends on dietary fat and adequate magnesium intake.

Key Points

Plant-Based Sources: Increase D2 levels by eating UV-exposed mushrooms and fortified plant-based milks, cereals, and orange juice.
Dietary Fat is Key: Vitamin D is fat-soluble, so consume D2 sources with healthy fats like nuts, seeds, or avocado to maximize absorption.
Consider Supplements: If dietary changes are insufficient, D2 supplements are available, including options for addressing significant deficiencies.
D2 vs. D3: While both are effective, research suggests D3 may be superior for raising and maintaining overall blood vitamin D levels, but D2 is a suitable vegan alternative.
Consult a Professional: Always talk to a healthcare provider before starting supplements to determine if supplementation is appropriate for you and monitor your vitamin D levels with a blood test.
Support with Magnesium: Adequate magnesium intake is necessary for the body to properly activate and utilize vitamin D, so include magnesium-rich foods in your diet.

Understanding Vitamin D2 (Ergocalciferol)

Vitamin D is a fat-soluble vitamin vital for calcium and phosphorus regulation, essential for bone health, and supports immune function and cell growth. Vitamin D exists in two main forms: D2 (ergocalciferol) and D3 (cholecalciferol).

Produced by plants and fungi exposed to UV light, vitamin D2 is a key source for vegans and vegetarians. Unlike D3, which comes primarily from animal sources and sun exposure, D2 is obtained through diet or supplements. Both forms are converted to an active state in the body, though D3 might be more effective at raising blood levels long-term.

Dietary Strategies to Increase Your D2 Levels

To effectively boost your vitamin D2 intake, include naturally rich and fortified plant-based foods in your diet.

Incorporating Naturally Occurring Sources

UV-Exposed Mushrooms: Mushrooms containing ergosterol convert it to vitamin D2 when exposed to UV light. Look for UV-treated varieties like Portobello, white button, and shiitake.
Yeast: Some yeasts also provide vitamin D2 after UV exposure.

Choosing Fortified Foods

Many plant-based products are fortified with vitamin D2. Always check labels.

Fortified D2 sources include:

Plant-Based Milks: Soy, almond, oat, and hemp milks are often fortified.
Orange Juice: Many brands add vitamin D.
Breakfast Cereals: Numerous cereals are fortified with vitamin D.
Margarine: Some margarines contain added vitamin D.

Maximizing Vitamin D Absorption and Supplementation

Supplements can be crucial if dietary intake is insufficient. Proper absorption enhances effectiveness.

Tips for Enhancing Absorption

Consume with Healthy Fats: As a fat-soluble vitamin, D2 is best absorbed with healthy fats from foods like avocados, nuts, or olive oil.
Ensure Adequate Magnesium: Magnesium is needed to activate vitamin D in the body. Consume magnesium-rich foods.
Time Your Intake: Taking vitamin D with your largest meal can improve absorption.

D2 vs. D3: A Comparison

The form of vitamin D matters, particularly for vegans.


Feature	Vitamin D2 (Ergocalciferol)	Vitamin D3 (Cholecalciferol)
Source	Plants, fungi (mushrooms), fortified foods	Animals (fatty fish, eggs), sun exposure
Availability	Prescription options available, used in fortification	Over-the-counter supplements, more common in food
Effectiveness	Can raise levels, possibly less potent or shorter duration than D3	May be more effective at raising and maintaining levels
Ideal For	Vegans, vegetarians, dietary restrictions	Those without dietary restrictions, generally considered better for overall levels
Cost	Often cheaper to produce	Can be slightly more expensive; vegan D3 from lichen exists

Working with Supplements

Supplements can help if diet is insufficient. Prescription D2 can address deficiencies. A healthcare provider can determine if supplementation is needed and recommend appropriate options based on blood tests. D2 supplements come in various forms.

Conclusion: A Holistic Approach to Boosting D2

Increasing vitamin D2 levels is achievable through diet and supplementation. For plant-based diets, focus on UV-exposed mushrooms and fortified products. D2 supplements are an option, though D3 might be more effective for overall vitamin D status. Maximize absorption by consuming with healthy fats and ensuring adequate magnesium. Always consult a healthcare professional before starting supplements to determine if supplementation is right for you and to monitor levels.

For more information on vitamin D, refer to the NIH Office of Dietary Supplements.

Frequently Asked Questions

UV-exposed mushrooms are one of the best natural food sources of vitamin D2, with varieties like portobello, white button, and shiitake containing significant amounts.

Yes, it is possible for vegans to get enough vitamin D2 from diet by regularly consuming UV-exposed mushrooms and a variety of fortified plant-based products like milks, cereals, and orange juice.

For those seeking to increase overall vitamin D levels, D3 is often considered more effective at raising and maintaining blood levels. However, D2 is a suitable option, especially for vegans, but it is best to discuss the choice with a healthcare provider.

Prescription-strength options of vitamin D2 (ergocalciferol) are available, often used to address severe deficiencies, while other options may be available without a prescription.

The time it takes for vitamin D levels to rise varies by individual and the severity of the deficiency. It is important to work with a healthcare provider who can monitor your levels.

Symptoms of vitamin D deficiency can be subtle but may include fatigue, bone and joint pain, muscle weakness or cramps, and mood changes like depression.

Yes, excessive intake of vitamin D from supplements can lead to toxicity (hypercalcemia). This can cause symptoms like nausea, weakness, and confusion.