Vitamin D is an essential nutrient that’s important for a balanced vegan diet. There are very few foods that naturally contain vitamin D. This makes it a nutrient of concern for the general population – vegans included.
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What is Vitamin D
Vitamin D is an essential fat-soluble vitamin that’s also considered a hormone due to its activity in the body.
Most essential nutrients are consumed through diet (food and drinks). Vitamin D is an interesting nutrient because it can be produced when skin is exposed to sunlight.
With modern lifestyles, people are often inside most of the day. This, along with other factors, makes it impractical for most people to rely on sun exposure alone for vitamin D.
Instead, large proportions of the population (particularly in countries far from the equator) rely on diet or supplements to meet vitamin D requirements.
What Does Vitamin D Do in the Body?
Vitamin D’s primary function is related to bone health and calcium balance 1, 2. It helps the body absorb and retain calcium 1, 2.
For years, this was the only known function of vitamin D. More recently, vitamin D has been found to impact other functions in the body and has been associated with many health conditions 2.
It seems vitamin D plays a role in gene transcription (cells division), cell growth, and helping the immune system fight infections 1, 2.
It may also play a role in inflammation and glucose metabolism 2 .
Vitamin D status or intake has been associated with some types of cancer, multiple sclerosis, fibromyalgia, rheumatoid arthritis, polycystic ovary syndrome, diabetes, high blood pressure and psoriasis 3, 4.
Studies have associated vitamin D with other health conditions too; however, association does not mean causation. We don’t know if low vitamin D levels cause these conditions, if these conditions lead to low vitamin D levels, or if another factor could be responsible.
How Much Vitamin D Do Vegans Need?
There are no specific vitamin D intake recommendations for vegans. Vegans should aim to meet vitamin D intake recommendations set out for the general population.
Current intake recommendations for vitamin D in adults under the age of 70 years is 600 IU per day (15 micrograms). Over the age of 70 years, recommendations increase to 800 IU per day (20 micrograms) 1, 2, 5.
This assumes minimal or zero formation of vitamin D from skin exposed to sunlight 1.
These recommendations are based primarily on the role vitamin D plays in bone health. Specifically, what levels of vitamin D in the blood are needed to have favorable outcomes, and how much vitamin D would an average person need to consume, to achieve these blood levels 1.
Researchers creating these recommendations found insufficient data to use any other marker of health in establishing vitamin D intake requirements 1.
Some research on other health impacts of vitamin D intake suggest slightly higher intakes would be favorable 6. While it was determined this additional research wasn’t robust enough to use in setting population targets of vitamin D intake, certain healthcare professionals suggest higher intakes are appropriate for some people 6.
Weight may play a role in how much vitamin D a person requires. Vitamin D needs may increase with higher body weights 2, 7, 8.
As with almost any nutrition topic, more is not always better. The recommendations for vitamin D intake also factor in studies that show high levels of vitamin D are also not favorable 1, 2, 7.
An upper limit for daily vitamin D intake in adults is 4000 IU 1, 2, 5.
Vitamin D Deficiency
Vitamin D deficiency leads to a condition called rickets in children, or osteomalacia in adults 3. Both are disorders of softening bones which relates to vitamin D’s role in calcium balance.
Severe deficiency can have impacts on the neuromuscular system with symptoms including muscle weakness, limb pain and impaired physical function 3.
Low vitamin D levels have been associated with many health conditions; however, more research is needed to determine if low vitamin D levels cause these conditions.
Vitamin D deficiency is generally caused by lack of exposure of unprotected skin to sunlight and/or inadequate intake of vitamin D from food sources and/ or supplements 3, 4.
Vitamin D deficiency is a common problem worldwide, particularly in countries further from the equator (above or below the 37th parallels), especially during the winter months 3.
Rates of vitamin D deficiency vary greatly and depend on numerous factors. When assessing blood levels of vitamin D, it seems the Canadian population has adequate vitamin D status 9.
Most people in the United States also seem to have adequate vitamin D status 2. However, up to 18 % of the population was found to be at risk of insufficient vitamin D and up to 5% at risk of vitamin D deficiency 2.
Are Vegans at Risk of Vitamin D Deficiency?
Research on vitamin D levels in vegans suggests that vegans have lower vitamin D levels compared to vegetarians and meat-eaters 10, 11.
However, these studies also showed that vitamin D levels in vegans were generally adequate, despite being lower overall 10, 11.
Based on this limited research, it seems that, on average, a vegan diet may lower vitamin D status but not to levels that suggest deficiency.
It’s unclear from these studies how vegans were getting vitamin D (through fortified foods, supplements and/or sun exposure). Regardless, it’s prudent for vegans to ensure a regular source of vitamin D in their diet/ lifestyle.
Vitamin D deficiency tends to be a population-wide problem, rather than a vegan-specific concern, as food sources and sunlight exposure are limited. It’s a nutrient of concern for both vegans and omnivores.
How Do Vegans Get Vitamin D?
With most nutrients, discussion on how to get enough focuses solely on food sources. With vitamin D, it’s also important to discuss sunlight exposure.
Can I Get Enough Vitamin D from the Sun?
There are numerous factors that limit someone’s ability to get adequate vitamin D from sunlight exposure: 3, 12
- Skin type: Darker skin requires longer sun exposure to create vitamin D.
- Season: Vitamin D levels tend to be highest in summer and autumn and lowest in winter and spring. The angle of the sun in winter months is inadequate for producing vitamin D.
- Latitude: People at higher latitude (further away from the equator) often cannot get adequate vitamin D from the sun during the winter. This has to do with the angle of the sunlight and that people cover their skin when it’s colder outside.
- Use of sunscreen: Sunscreen blocks the skin from producing vitamin D. Skin needs exposure to the UV radiation in sunlight to create vitamin D and sunscreen blocks the UV radiation.
- Time of day: Skin exposure to sunlight between 10 am and 2 pm is best for vitamin D production (many people are inside working during these hours).
- Covering the skin: Wearing clothing that covers most or all skin prevents vitamin D production as the skin isn’t exposed to sunlight. This is a problem during the colder months but also in warmer months if people dress modestly for cultural, personal or religious reasons.
- Age: With age, the skin becomes less able to produce vitamin D from sunlight exposure.
- Smog and clouds: These limit UV radiation (which the skin needs to produce vitamin D).
Most people are impacted by one or more factors that limit the ability to get adequate vitamin D from sunlight.
This is why, when creating vitamin D intake recommendations, it was assumed that minimal to no vitamin D was available through sunlight exposure on skin 1, 5.
Furthermore, due to the risk of skin cancer, some health authorities do not recommend any direct sunlight exposure, even to help meet vitamin D intake requirements 13. Instead, they recommend meeting vitamin D requirements through food or supplements 13.
Getting vitamin D from fortified foods or supplements is reliable and effective.
Some healthcare providers still recommend sun exposure for vitamin D. Typically, the recommendations are to expose skin to sunlight for short periods of time each day, then use protective measures (sunscreen, clothing) to protect skin from sunburn.
Exposing arms and face, or an equivalent amount of skin, for 10-15 minutes per day for light-skinned people or 20 minutes per day for dark-skinned people is thought to produce adequate vitamin D 14.
Vitamin D production from skin decreases with age and many health authorities recommend older adults supplement with vitamin D. The age to start supplementing varies but Health Canada recommends starting at age 51 12.
During winter months, at higher latitudes in particular, fortified foods and/or vitamin D supplements are likely required.
Vegan Foods with Vitamin D
There are very few foods that naturally contain vitamin D, vegan or otherwise.
The highest sources of naturally occurring vitamin D are found in animal-based foods (fish, liver, eggs and cheese).
Many vegans promote mushrooms as a source of vitamin D however, mushrooms are only a good source of vitamin D if they’ve been treated with UV radiation. This is like how humans produce vitamin D from sun exposure (UV radiation).
In Canada, I’ve yet to see UV treated mushroom (also known as irradiated mushrooms) for sale. They may be available elsewhere, but you should assume that unless the packaging specifies treatment with UV radiation (irradiated) they only provide minimal vitamin D.
Beyond mushrooms, the only other source of vitamin D in a vegan diet is from fortified foods.
Fortification rules vary depending on where you live, but if a food is fortified with vitamin D, it should be listed in the ingredient list. The amount of vitamin D should also be on a nutrition facts panel.
In Canada, the only vegan product with mandatory vitamin D fortification is margarine and “other similar substitutes for butter” 15. Many dairy alternatives and other vegan foods are fortified but you must check the label to find out.
It’s likely challenging to meet vitamin D requirements from food sources alone on a vegan (or omnivore) diet, which is why supplementation is often recommended for vegans, and the general population (especially with minimal sun exposure and/or in the winter) 12, 14.
Do Vegans Need a Vitamin D Supplement?
It’s important for vegans, and the general population, to meet vitamin D intake requirements. There are 3 ways to do this:
- Fortified foods
- Sun exposure
Getting adequate vitamin D from vegan foods may be a challenge unless you regularly consume fortified foods in large enough quantities. Remember that mushrooms are a poor source of vitamin D unless they’re irradiated (which is often not a standard practice).
Sun exposure is another option but is impractical and limited for most people. It may increase your risk of skin cancer and is ineffective during the winter months at higher latitudes.
This leaves supplements as a reliable, simple solution for meeting vitamin D requirements for vegans and others.
Always speak to your doctor before starting any new supplements.
Many health experts recommend vitamin D supplements, especially during the winter months when sunlight exposure is ineffective (at higher latitudes especially) 14, 16.
How Much Vitamin D to Take as a Vegan
There are no standard recommendations for doses of vitamin D supplements for vegans (or the general population).
Vitamin D recommendations are set assuming zero sun exposure; however, you’ll produce at least some vitamin D from the sun unless your skin is never exposed to sunlight.
Also, target intake requirements include vitamin D from food sources and supplements combined. If you regularly consume vitamin D fortified foods, a smaller vitamin D supplement may be adequate.
If fortified foods are not regularly consumed, aiming for the recommended daily intake amount in a supplement may be a good target 6, 12, 14.
As always, speak with your primary care provider before starting any supplements.
Remember that current intake recommendations for vitamin D in adults under the age of 70 years is 600 IU per day (15 micrograms) and 800 IU per day (20 micrograms) over the age of 70 1, 2, 5.
There is also an upper limit for vitamin D intake set at 4000 IU for adults. Intake over this amount may be harmful and shouldn’t be taken without close medical supervision 1, 2, 5.
I’ve seen vitamin D supplements with doses at or above this upper limit, so caution is warranted.
When is the Best Time to Take a Vitamin D Supplement?
Vitamin D is fat-soluble and the body absorbs it the same way as other dietary fats.
Research shows that vitamin D supplements are best absorbed when taken with the largest meal of the day 17.
Other research demonstrates that a meal higher in fat increases vitamin D absorption compared to a lower fat meal 18. This study used roughly 26 grams of fat versus about 2 grams of fat in the test meals 18.
These two studies suggest that consuming a source of fat when taking a vitamin D supplement is likely the best timing to improve absorption.
This means it’s best to take vitamin D supplements with a meal or snack that contains fat. Your largest meal of the day may be the best choice; I assume this is because the largest meal often also contains the greatest fat content.
Absorption of essential fat-soluble nutrients is one of the many reasons why it’s important to regularly include healthy fats in the diet.
Is Vitamin D3 Vegan?
A final consideration when talking about vitamin D supplements for vegans is whether vitamin D3 is vegan.
There are two forms of vitamin D:
- Vitamin D2 (ergocalciferol)
- Vitamin D3 (cholecalciferol)
Vitamin D2 is always vegan. Vegan foods fortified with vitamin D typically use vitamin D2.
Most other vitamin D fortified foods, and most vitamin D supplements, use vitamin D3. It should be assumed that vitamin D3 used in fortification or supplements is not vegan unless specified.
For a long time, vegans needed to rely solely on vitamin D2 supplements. There are now many vegan vitamin D3 supplements on the market.
There has been lots of debate, and research, on the function of vitamin D2 vs D3 in terms of how well either option works for raising and maintaining vitamin D levels in blood.
Most health authorities agree that both options are viable and can work to maintain vitamin D levels 2. While both can be effective, it seems that D3 may have some advantages over D2 19.
There are an abundance of vegan vitamin D3 supplements, and they may be the best choice if you decide to supplement (after speaking with your primary care provider first).
Summary: Vegan Vitamin D
Vitamin D is an essential nutrient that’s challenging to get adequate amounts of due to low sun exposure and limited food sources (vegan or otherwise).
If fortified foods and adequate sun exposure are not possible (or practical), supplements may be required. Sun exposure is not effective at higher latitudes during the winter months, therefore supplements or fortified foods are needed for a large portion of the population especially during winter.
Vegans can choose vitamin D2 supplements, which are always vegan, or specialty vegan vitamin D3 options. Unless otherwise specified, vitamin D3 in fortified foods or supplements is not vegan.
Always speak with a doctor before changing your diet or taking new supplements. Please read our full website disclaimer.
- Dietary reference values for Vitamin D (EFSA)
- Vitamin D: Fact Sheet for Health Professionals
- Not enough vitamin D: Health consequences for Canadians
- Sunlight and vitamin D
- Dietary reference intakes: Table 1 – Reference values for vitamins
- Evaluation, treatment, and prevention of vitamin D deficiency: An Endocrine Society clinical practice guideline
- Optimal vitamin D supplementation doses that minimize the risk for both low and high serum 25-hydroxyvitamin D concentrations in the general population
- The importance of body weight for the dose response relationship of oral vitamin D supplementation and serum 25-hyroxyvitamin D in healthy volunteers
- Vitamin D and calcium: Updated dietary reference intakes
- Association between plasma 25-hydroxyvitamin D levels and fracture risk: The EPIC-Oxford study
- Bone turnover, calcium homeostasis, and vitamin D status in Danish vegans
- Vitamin D (Health Canada)
- Vitamin D and sun protection: What you need to know
- Daily needs (VeganHealth)
- Foods to which vitamins, mineral nutrients and amino acids may or must be added
- Protecting bone health on a vegan diet
- Taking vitamin D with the largest meal improves absorption and results in higher serum levels of 25-hyrodxyvitamin D
- Effect of high- versus low-fat meal on serum 25-hydroxyvitamin D levels after a single oral dose of vitamin D: A single-blind, parallel, randomized trial
- Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: A systematic review and meta-analysis
This reference list is not intended to be comprehensive.
About Nicole Stevens
Nicole is a vegan Registered Dietitian (RD) and founder of Lettuce Veg Out.
She helps people thrive on a vegan diet with balanced recipes and easy-to-understand nutrition science.
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