Can we meet vitamin D needs through food, or do we need sun, and supplements?
How much vitamin D do we need per day?
According to the US Department of National Health & Human Services, most people need approximately 15 mcg or 600 IU of vitamin D per day (1).
Elderly people need a little more, 20 mcg or 800 IU.
What are the health benefits of vitamin D?
Vitamin D is so important for the human body.
For instance, vitamin D plays an important role on cell growth, neuromuscular function, immune function, and reduction of inflammation (1).
Most noteworthy, vitamin D has linked to the prevention of:
- bone and teeth loss. Vitamin D promotes calcium absorption. Also, it regulates calcium and phosphate in the blood, as they are needed for normal bone growth.
- osteoporosis. Vitamin D may protect elderly people from osteoporosis.
- cancer. Vitamin D can decrease the risk for certain cancers, such as colon, prostate, and breast cancer.
Moreover, there are studies that showed that vitamin D might play some role in the prevention and treatment of type 1 and type 2 diabetes, hypertension, glucose intolerance, and multiple sclerosis (1).
Are animal sources indeed rich in vitamin D?
Even meat-eaters and vegetarians can’t get adequate amounts of vitamin D through food.
Very few foods contain vitamin D.
Maybe fortified foods with vitamin D help most people meet the daily vitamin D needs.
But, what animal foods naturally contain vitamin D?
Certainly fatty fish are the best source of vitamin D. Beef liver, cheese, and egg yolks provide only small amounts.
According to the USDA:
|Vitamin D (mcg)|
per 100 gr)
|Vitamin D (IU)|
per 100 gr
|% DV |
|cod liver oil||250||10000||1667|
As you can see, only fatty fish contains adequate amounts of vitamin D.
Why we shouldn’t depend on animal foods for vitamin D intake?
Certainly, eating fish, meat, and dairy for vitamin D isn’t the best option.
Why you should avoid fish consumption?
Firstly, fish don’t have fiber, and they are low in antioxidants, compared to fruits, vegetables, beans, spices, or herbs.
On the other hand, fish contain cholesterol, saturated fat, and above all, fish are polluted with heavy metals.
Why you can’t depend on meat & dairy for vitamin D?
Meet, and dairy aren’t good sources of vitamin D.
Moreover, only specific parts of animals contain some amounts of vitamin D (2).
In many cases, animals are supplemented with vitamin D, just for marketing purposes.
Furthermore, many believe that eggs are a good source of vitamin D.
1 egg yolk contains 0.9 mcg of vitamin D. That’s 6% DV.
But, when eating an egg yolk, you consume 184 mg of cholesterol, and 1.6 gr of saturated fat, as well.
Increased saturated fat has linked to increased risk of heart disease and stroke.
Therefore, the American Heart Association recommends no more than 13 grams of saturated fat per day.
Meat, egg, and dairy provides only a small percentage of vitamin D, but they are packed with saturated fat. Better avoid them.
You still think that cow’s milk is good for you? Find out, why you should switch to vegan milks here.
Nowadays, many vegan milks are fortified with vitamin D, as well.
Do animals produce vitamin D?
Many animals synthesize vitamin D in the skin. Just like human.
Contrary, fish don’t synthesize vitamin D. They depend on their food. Wild fish eat plankton that contains vitamin D. Farmed fish are fed formulated diets that contain vitamin D (3).
Fish store vitamin D in liver and fat tissues.
However, according to a research, fish may contain less vitamin D than the amount of vitamin D in food charts (4). That’s mainly due to the different diets of fish.
Therefore, you can’t be sure that you consume a specific amount of vitamin D from fish.
Vegan foods rich in vitamin D
Vitamin D is indeed rare in food. Especially vegan foods.
There’s only a vegan option for vitamin D, mushrooms.
Furthermore, only some mushrooms contain adequate amounts of vitamin D. Maitake, chanterelle, and morel are the only mushroom varieties that are high in vitamin D. They can indeed help us meet the vitamin D daily needs.
|Vitamin D (mcg) |
per 100 gr)
|Vitamin D (IU) |
per 100 gr
|% DV |
Moreover, some producers expose mushrooms to ultraviolet light. This way they produce more vitamin D naturally (5).
Are fortified products good for you?
Certainly the most common vitamin D sources, for vegans, vegetarians, and meat-eaters are fortified products.
Nowadays, many foods are fortified with vitamin D.
For instance, you can find many fortified with vitamin D foods, such as tofu, orange juice, cow’s milk, or any vegan milks.
Therefore, fortified foods may be important for meeting the daily vitamin D needs.
How much vitamin D do we get from the sun?
The human body synthesize vitamin D when skin exposed to sunlight.
For some people, sunlight may be a major source of vitamin D.
Furthermore, the human body stores vitamin D in the liver and fat tissue.
People who are exposed to sunlight during summer, fall, and spring may store adequate amounts of vitamin D for the winter. Research has shown that even people who live in norther areas can form enough vitamin D.
Moreover, there isn’t such thing as excessive sun exposure. We can’t get too much vitamin D from sunlight. The heat on the skin inhibits the formation of vitamin D (1).
How long do you need to be in the sun to get vitamin D?
There isn’t a recommended daily sunlight exposure, as vitamin D synthesis depends on many factors:
- time of day,
- length of day,
- cloud cover,
- skin melanin content, and
All these factors affect UV radiation exposure. Therefore, vitamin D synthesis.
Practically, 30 minutes of sun exposure daily are considered enough. Even less may be enough.
Certainly, avoid exposing any part of the body to sunlight after 1 pm, without using sunlight protection.
Every year, there are approximately 1.5 million skin cancers. As, UV radiation is a carcinogen, protect your skin when exposure to sunlight.
Can vitamin C protect from skin cancer & melanoma?
Vitamin C is a powerful natural antioxidant.
It has gained popularity in dermatology. Moreover, vitamin C may help fight tissue inflammation, free radicals, and photoaging.
Also, vitamin C may promote tissue healing, and stimulate collagen synthesis (6).
Most noteworthy, vitamin C may help to inhibit the invasion and metastasis of melanoma (7).
Therefore, consume more foods rich in vitamin C during summer.
See the whole list, here.
Can I get vitamin D on a cloudy or rainy day?
Vitamin D is produced when Ultraviolet B (UVB) radiation, with a wavelength of 290–320 nm penetrates skin.
On a cloudy day the energy of the radiation is reduced by 50%.
Shade or air pollution may reduce it up to 60%.
Can I get vitamin D indoors?
If you’re in a building you won’t synthesize any vitamin D. Not even if you’re in a sunny room.
UVB radiation doesn’t penetrate glass.
Do sunscreens inhibit vitamin D formation?
As a rule of thumb, sunscreens block the UV rays that produce vitamin D.
Moreover, you should prefer sunscreen with a sun protection factor (SPF) of 8 or more.
On the other hand, studies have shown that most people fail to cover skin properly.
Most commonly, we don’t cover all the exposed skin, or we forget to put sunscreen regularly.
Should I take vitamin D supplements?
According to the American Office of Dietary Supplements, most people shouldn’t consume more than 4,000 IU (100 mcg) of vitamin D (1).
This dosage may be conservative, as excess vitamin D has linked to many health problems. Vitamin D is fat-soluble, so it accumulates in body fat.
On the other hand, vitamin D toxicity is rather unlikely to happen at dosages below 10,000 IU per day (1).
Furthermore, vitamin D toxicity may happen only from supplements, not exposure to sunlight, or from food (1).
In any case, consult your physician, especially if you’re under medication.
How to increase absorption of vitamin D supplements?
Maybe it’s a good idea to consume vitamin D supplements with food.
Above all, you should consume some fat.
A 2015 study showed that people who consumed dietary fat with the vitamin D supplementation increased the vitamin D absorption up to 32%.
The best dietary sources of fat are seeds and nuts. Prefer them as a fat source. They are rich in many nutrients.
For instance, walnuts, chia seeds, and flaxseeds are high in omega-3 fatty acids. Moreover, sunflower, pumpkin, and hemp seeds are high in zinc.
So, does vegan foods provide enough vitamin D?
Mushrooms, the only vegan food that contain vitamin D shouldn’t be considered sufficient vitamin D source.
Also, you can prefer fortified foods.
Most noteworthy, the human body can synthesize adequate amounts of vitamin D from sunlight.
If you have low serum vitamin D, consult your physician. Maybe vitamin D supplementation is a good solution, especially if you’re living in a cloudy place.
- National Institutes of Health, Office of Dietary Supplements: Vitamin D.
- Oxford Academic: Natural vitamin D Content in Animal Products.
- Aquaculture nutrition: The significance of vitamin D for fish: A review.
- Boston University Medical Center: An Evaluation of the Vitamin D3 Content in Fish: Is the vitamin D Content Adequate to Satisfy the Dietary Requirement for vitamin D?
- Curtin University, Perth: A Review of Mushrooms as a Potential Source of Dietary vitamin D.
- NCBI: Vitamin C in dermatology
- PMC: Role of vitamin C in Skin Diseases