How much vitamin D do vegetarians need daily?

December 27, 2025 •

5 min read

Studies have shown that vegetarians and vegans often have lower blood concentrations of 25-hydroxyvitamin D, the primary indicator of vitamin D status, compared to meat-eaters, underscoring a critical dietary consideration. This can impact overall health, from bone density and immune function to mood regulation.

Quick Summary

Understanding vitamin D needs is crucial for vegetarians to maintain bone health and immunity. This guide outlines recommended daily intakes, identifies vegetarian sources, and explains how to address potential deficiencies through diet, sunlight, and supplementation.

Key Points

Standard Daily Intake: For most adults, the recommended daily allowance (RDA) is 600-800 IU (15-20 mcg), regardless of dietary pattern.
Higher Risk for Vegetarians: Due to the exclusion of primary animal-based sources like fatty fish, vegetarians (especially vegans) have a higher risk of deficiency and must be more vigilant about their intake.
Leverage Fortified Foods: Incorporate vitamin D-fortified foods such as plant-based milks, cereals, and orange juice into your daily diet.
Utilize UV-Exposed Mushrooms: UV-exposed mushrooms, including maitake and shiitake, are one of the few natural plant-based sources of vitamin D2.
Consider Supplements: When diet and sun exposure are insufficient, supplements (vitamin D2 or vegan D3) are a reliable option; consult a healthcare provider for dosage advice.
Embrace Sunlight Strategically: Safe, moderate sun exposure remains a key way for the body to synthesize vitamin D naturally, though effectiveness varies with skin type and location.
Enhance Absorption: Take vitamin D with healthy fats like nuts, seeds, or avocado to improve absorption, as it is a fat-soluble vitamin.

The Recommended Daily Vitamin D Intake for Vegetarians

The recommended daily allowance (RDA) for vitamin D is generally consistent across dietary patterns, including vegetarianism, as the primary source for most people is sunlight, not diet. For adults aged 19–70, the standard recommendation is 600 International Units (IU), equivalent to 15 micrograms (mcg) per day. This increases to 800 IU (20 mcg) for adults over 70. However, since many of the richest natural dietary sources are animal-based (like fatty fish), vegetarians and especially vegans must be more mindful of their intake and may require strategic supplementation. Factors like limited sun exposure, darker skin pigmentation, and age can increase the risk of deficiency for anyone, making conscious intake particularly important for those on plant-based diets.

Why Vegetarians Face a Higher Risk of Deficiency

While the RDA is the same, the risk profile for vitamin D deficiency is different for vegetarians. The reason for this increased risk lies in the limited availability of natural food sources. Foods that are naturally high in vitamin D include oily fish, cod liver oil, and eggs from chickens with sun exposure. Vegetarians who consume dairy and eggs (lacto-ovo vegetarians) have more options but are still often at a disadvantage compared to omnivores. Vegans, who exclude all animal products, face the most significant challenge, as very few plant-based foods naturally contain vitamin D. This makes fortification and supplementation key strategies for maintaining optimal levels. A study among British adults found that vegans had the lowest mean plasma vitamin D concentrations, with a notably higher prevalence of deficiency during winter and spring compared to omnivores.

Primary Sources of Vitamin D for Vegetarians

To ensure adequate intake, vegetarians must focus on specific food sources and lifestyle habits. Here is a comprehensive list of ways to get vitamin D:

UV-Exposed Mushrooms: Certain mushrooms, such as maitake and shiitake, naturally contain ergosterol, which converts to vitamin D2 when exposed to ultraviolet (UV) light. Some brands of mushrooms are treated with UV light to increase their vitamin D content. This can provide a significant boost, with a half-cup of UV-exposed white mushrooms potentially containing hundreds of IUs.
Fortified Plant-Based Milks and Cereals: Many plant-based milk alternatives, including soy, almond, and oat milk, are fortified with vitamin D. Similarly, a wide variety of breakfast cereals are fortified with vitamins and minerals, including vitamin D2. Always check the nutrition label to confirm fortification.
Fortified Orange Juice: Some brands of orange juice also come fortified with vitamin D and calcium, offering another convenient option for a quick boost.
Eggs and Dairy (for lacto-ovo vegetarians): For vegetarians who consume them, egg yolks provide a modest amount of vitamin D, especially from hens with outdoor access. Cow's milk is often fortified with vitamin D in many countries. Some cheeses, like cheddar and ricotta, naturally contain small amounts.
Sunlight: Exposure to sunlight is the most natural way to produce vitamin D. The body synthesizes vitamin D3 when the skin is exposed to UV-B rays. A short period of midday sun exposure (5–30 minutes, depending on skin type, location, and season) a few times per week is often sufficient for many people. However, factors like darker skin, age, latitude, and consistent sunscreen use can limit production.

Supplementation Strategies for Vegetarians

When dietary sources and sunlight are insufficient, which is common during winter months or in less sunny climates, supplementation becomes a critical tool. Vegetarian-friendly supplements are widely available in two forms: vitamin D2 and vitamin D3.

Vitamin D2 (Ergocalciferol): This form is derived from fungal sources like yeast and is always suitable for vegetarians and vegans. While effective, some studies suggest it may be slightly less potent at raising and maintaining blood vitamin D levels compared to D3.
Vegan Vitamin D3 (Cholecalciferol): Traditionally, D3 was sourced from lanolin (sheep's wool) or fish oil, but vegan D3 derived from lichen is now readily available. Many brands offer this plant-based option, which is considered more bioavailable and effective than D2. Always read labels to ensure the source is vegan-friendly.

Comparison of Vitamin D Types


Feature	Vitamin D2 (Ergocalciferol)	Vitamin D3 (Cholecalciferol)
Source	Produced from fungi and yeast.	Derived from lanolin (sheep's wool), fish oil, or vegan sources like lichen.
Efficacy	Effective at raising vitamin D levels, though possibly less potent than D3.	More effective at raising and maintaining blood levels of vitamin D.
Absorption	Generally well-absorbed.	Often considered more bioavailable and potent for the human body.
Vegetarian/Vegan Suitability	Always suitable for vegetarians and vegans.	Vegan-friendly versions (from lichen) exist; check product labels.

Maximizing Vitamin D Absorption and Overall Health

Ensuring you get enough vitamin D is not just about intake; proper absorption is also essential. As a fat-soluble vitamin, D is best absorbed when consumed with healthy fats. Pairing fortified plant milk or a vitamin D supplement with a meal containing nuts, seeds, or avocado can help optimize absorption. Additionally, maintaining good gut health through a balanced diet rich in fiber and probiotics can aid in nutrient uptake.

Regular blood tests to check your vitamin D levels are advisable, especially if you have risk factors for deficiency or are concerned about your intake. This allows for personalized, data-driven supplementation under the guidance of a healthcare professional. Remember that optimal vitamin D status contributes not only to strong bones but also to robust immune function and mental well-being. By being proactive and informed, vegetarians can effectively meet their daily vitamin D needs and support their overall health. For further information on recommended intake levels, see the NIH Office of Dietary Supplements fact sheet.

Conclusion

While vegetarians, particularly vegans, face unique challenges in obtaining sufficient vitamin D from diet alone, meeting the recommended daily intake is entirely achievable through a combination of smart dietary choices, strategic sun exposure, and, when necessary, supplementation. Focusing on fortified plant-based foods, consuming UV-exposed mushrooms, and using vegan-friendly supplements can help bridge the nutritional gap. Regular blood level monitoring and mindful lifestyle habits, such as enjoying safe sunlight, will ensure vegetarians maintain healthy vitamin D levels for strong bones, a healthy immune system, and overall vitality.

Frequently Asked Questions

The recommended daily allowance (RDA) for vitamin D is 600 IU (15 mcg) for adults aged 19-70 and 800 IU (20 mcg) for those over 70. This is the same for vegetarians and non-vegetarians, though vegetarians must be more mindful of achieving this from non-animal sources.

Excellent vegetarian sources include UV-exposed mushrooms, fortified plant-based milks (soy, almond, oat), fortified orange juice, and fortified breakfast cereals. For lacto-ovo vegetarians, eggs from sun-exposed chickens and some cheeses also contribute.

Both D2 and D3 effectively raise vitamin D levels, but D3 is generally considered more potent. Vegan D3 derived from lichen is available, making it the preferred choice for those seeking maximum efficacy from a plant-based source.

Sunlight is a major source, but relying on it alone is unreliable due to factors like latitude, season, time of day, skin pigmentation, and sunscreen use. Dietary intake from fortified foods and/or supplements is often necessary to ensure adequate levels.

Given the limited natural sources in a plant-based diet and the unreliability of sun exposure, supplementation is often recommended for vegetarians, especially during winter months. Consult a healthcare provider to determine the right dosage for your needs.

Individuals with darker skin produce less vitamin D from sunlight and should prioritize fortified foods and consider supplements. They may require longer sun exposure than those with lighter skin to produce the same amount of vitamin D.

Symptoms can be subtle and include fatigue, muscle weakness or cramps, bone pain (especially in the lower back), and mood changes like depression. Severe, prolonged deficiency can lead to bone loss, osteoporosis, and an increased risk of fractures.

No, fortification is not universal. Always check the nutrition label of plant-based milks, cereals, and other products to confirm they have been enriched with vitamin D.