How to Increase Vitamin D as a Vegetarian: A Complete Guide

December 5, 2025 •

4 min read

Over one billion people worldwide are estimated to be vitamin D deficient, a risk that can be higher for vegetarians due to dietary restrictions. Understanding how to increase vitamin D as a vegetarian is crucial for maintaining bone strength, immune function, and overall well-being. This guide offers actionable advice to help you meet your needs.

Quick Summary

Vegetarians can increase vitamin D by combining safe sun exposure, consuming fortified foods like plant-based milks and cereals, incorporating UV-exposed mushrooms, and using specific supplements.

Key Points

Sunlight Exposure: The most natural way to produce vitamin D is through safe sun exposure, with 10-30 minutes several times per week often being sufficient.
Fortified Foods: Many vegetarians rely on fortified products like plant-based milks, cereals, and orange juice to meet their daily needs.
UV-Exposed Mushrooms: Certain mushrooms, like shiitake and maitake, produce vitamin D2 when exposed to UV light, offering a plant-based food source.
Supplementation: Supplements are often necessary, especially during winter or for those with limited sun exposure. Look for plant-derived D2 or lichen-sourced D3.
Enhance Absorption: Vitamin D is fat-soluble, so consuming sources with healthy fats like nuts or avocado can improve its absorption.
Check Labels: Not all products are fortified. Always check the nutrition label to confirm vitamin D content and suitability for your dietary needs.

Understanding the Vitamin D Challenge for Vegetarians

Vitamin D, often called the 'sunshine vitamin,' is unique because our bodies can produce it when skin is exposed to sunlight. However, natural dietary sources are predominantly animal-based, such as oily fish, fish oil, and eggs. This means vegetarians and, more specifically, vegans, must be intentional about their intake to avoid deficiency. A deficiency can lead to a weakened immune system, bone pain, muscle weakness, and increased risk of fractures.

Harnessing the Sun: Your Natural Vitamin D Source

Sunlight is arguably the most efficient and natural way to get vitamin D. When ultraviolet B (UVB) rays from the sun hit the skin, they trigger the synthesis of vitamin D3.

Here's how to make the most of sun exposure:

Aim for 10–30 minutes of midday sun exposure to your face, arms, and legs, several times a week. Midday offers the most effective UVB rays. Individuals with darker skin require longer exposure due to higher melanin levels.
Note that factors like geographic location, season, cloud cover, and sunscreen use can affect how much vitamin D your body produces.
Do not overdo it. Always protect your skin from sunburn by limiting prolonged exposure and using sunscreen, as skin health is also a priority.

Fortified Foods: Bridging the Dietary Gap

Because natural vegetarian food sources are limited, fortified foods are a cornerstone of a vitamin D-rich diet. The fortification process adds vitamin D to food items that don't naturally contain it.

Dairy and Plant-Based Milks

Both cow's milk and many plant-based alternatives are routinely fortified. Fortified cow's milk can contain 150-200 IU of vitamin D per cup. Lacto-vegetarians can also find fortified yogurt and cheese. For vegans, many brands of soy, almond, oat, and rice milks are fortified, offering around 100-144 IU per cup.

Breakfast Cereals and Juices

Breakfast cereals and brands of oatmeal are frequently fortified with vitamin D. The amount can vary widely by brand, so checking the nutrition label is essential. Similarly, some orange juices are fortified and can provide a decent amount of vitamin D, but not all brands fortify their products.

Tofu and Other Products

Some tofu products are fortified with vitamin D, making them an excellent source for vegans and a great addition to stir-fries, scrambles, and curries. Certain margarines are also fortified, unlike butter, which typically is not.

Unconventional Plant Sources: UV-Treated Mushrooms

Certain mushrooms are a unique and natural plant-based source of vitamin D2. Similar to human skin, mushrooms can produce vitamin D when exposed to UV light. Studies have shown that exposing specific types of mushrooms, such as maitake and shiitake, to UV light can significantly increase their vitamin D content. Some UV-exposed mushrooms can contain several hundred IU per serving. Cooking does not significantly reduce this vitamin D content, making them a fantastic and natural food option.

Vegetarian-Friendly Supplements

For many, especially during winter or with limited sun exposure, supplements are the most reliable way to ensure adequate intake. There are two main types of vitamin D supplements: D2 (ergocalciferol) and D3 (cholecalciferol).

Vitamin D2: Derived from plants like yeast or mushrooms, this is a reliably vegetarian and vegan-friendly option.
Vitamin D3: While most D3 is animal-derived, from sources like lanolin (sheep's wool fat) or fish oil, vegan D3 supplements are available. These are typically sourced from lichen. Research suggests D3 might be slightly more effective at raising blood levels, but both are useful.

Always consult a healthcare professional to determine the right dosage for your needs, as recommended daily intake varies by age and health status.

Comparison Table: Vegetarian Vitamin D Sources


Source	Type	Suitability	Notes
Sunlight	Natural	All vegetarians	Most effective way for many people; varies by season, skin tone, and location.
UV-Treated Mushrooms	Natural	Vegan, Lacto-Ovo-Vegetarian	A powerful, natural plant source of D2; content boosted by UV exposure.
Fortified Plant-Based Milks	Fortified	Vegan, Lacto-Ovo-Vegetarian	Soy, almond, oat, etc. Check labels for fortification as not all brands include it.
Fortified Breakfast Cereals	Fortified	Vegan, Lacto-Ovo-Vegetarian	Convenient source; fortification levels vary widely by brand.
Fortified Tofu	Fortified	Vegan, Lacto-Ovo-Vegetarian	Check labels for fortification; a great addition to meals.
Egg Yolks	Natural	Lacto-Ovo-Vegetarian	Provides a small amount of D, especially from free-range chickens.
Vegan D3 Supplements	Supplement	Vegan, Lacto-Ovo-Vegetarian	Derived from lichen, offers an animal-free D3 option.

Optimizing Absorption and Planning Your Intake

Vitamin D is a fat-soluble vitamin, meaning it is best absorbed when consumed with dietary fat. Incorporating healthy fats from sources like avocados, nuts, seeds, or fortified milks with your vitamin D sources can maximize absorption. Planning a balanced diet that includes these diverse sources throughout the day is key to ensuring consistent vitamin D intake, alongside regular, safe sun exposure. For a comprehensive overview of vitamin D and intake recommendations, consult authoritative sources like the National Institutes of Health (NIH).

Conclusion: A Multi-Pronged Approach for Vegetarians

While a vegetarian diet presents specific challenges for adequate vitamin D intake, it is entirely manageable with a strategic, multi-pronged approach. By combining regular, safe sun exposure with a consistent intake of fortified foods and, when necessary, appropriate supplementation, vegetarians can maintain optimal vitamin D levels. The key lies in diversifying your sources and remaining vigilant in a world where deficiency is all too common. Regular monitoring with a healthcare provider can also help tailor your strategy to your unique needs, ensuring you reap the wide-ranging benefits of this essential nutrient for strong bones and a resilient immune system.

Frequently Asked Questions

Most experts suggest 10 to 30 minutes of midday sun exposure to the face, arms, and legs, several times a week, is adequate for many people, though this can vary based on skin tone, location, and time of year.

No, some vitamin D3 supplements are sourced from animal products like sheep's wool lanolin or fish oil. Vegetarians and vegans should specifically seek out D2 or lichen-based D3 supplements.

Yes, specific types of mushrooms, such as maitake and shiitake, can produce significant amounts of vitamin D2 when exposed to UV light. Some UV-exposed mushrooms contain as much as 95% of the RDA per serving.

Some studies suggest that D3 might be more effective at raising and maintaining vitamin D blood levels, but both D2 and D3 are used by the body. For vegetarians, plant-sourced D2 and lichen-based D3 are both viable options.

While fortified foods like milk, cereals, and plant-based drinks are a valuable source, they typically provide a smaller amount of vitamin D per serving. They should be considered part of a broader strategy including sun exposure and/or supplements.

Symptoms can include fatigue, bone and muscle pain, muscle weakness, and a higher frequency of illness. If you experience these signs, it is wise to consult a doctor.

In many regions, especially those with limited winter sunlight, supplementation is recommended during autumn and winter. Those with consistently limited sun exposure, darker skin, or confirmed deficiency may need year-round supplementation, as advised by a healthcare professional.