One thing I think it’s fair to say happens when we undertake a vegan lifestyle is just how many of our friends and family suddenly become nutritionists. Ok so I am being a bit facetious but it is certainly true that’s as a meat eater nobody ever asked where I got my fibre from. I never had anyone ask me about phytonutrients, vitamins, minerals or flavonoids. But as soon as I became vegan they wanted to know where my protein came from. They just knew I would be B12 deficient and along with the “top two” came questions about vegan sources of vitamin D. So let’s answer that question for them and see where vitamin D comes from, why we need it and explore what are the best vegan sources vitamin D.
What is vitamin D?
Vitamin D, along with vitamins K, A and E is one of the fat-soluble vitamins and is sometimes known as the sunshine vitamin. This is because vitamin D sources are scarce in food and sun exposure is the optimum way to ensure sufficient levels. Vitamin D deficiency is quite common, more so in certain parts of the world than others. People who live further from the equator have an increased risk of deficiency and it is estimated that around 70% of both the UK and US populations are lacking in vitamin D.
The fact that deficiency is so common doesn’t mean it should be taken lightly. Vitamin D plays various essential roles within the body and a deficiency can cause serious health problems. Some of these roles include helping with the health of bones and teeth by maintaining blood levels of calcium and phosphorus. Supporting the health of the immune system as well as brain, and nervous system. Helping to regulate insulin levels and supporting lung function and cardiovascular health.
So, as you can see Vitamin D is essential for optimum health. So how do we go about getting enough if we are vegan?
A vitamin or a hormone? It comes from the sun
Even though vitamin D is called, vitamin D it is actually considered a pro-hormone and not really a vitamin. Vitamins are nutrients that typically cannot be created by the body and therefore must be obtained via our diet. Our skin however produces vitamin D when exposed to sunlight. A compound in our skin is activated by the UVB sun exposure.
Once activated it pays a visit to the liver and then the kidneys and is transformed in to the active form of vitamin D that we require. Sun exposure is the optimum way to ensure sufficient levels of vitamin D. It is estimated sun exposure on bare skin for 10-15 minutes, 2-3 times per week is sufficient for the majority of people. This will vary depending on your location, the strength of the sun and your skin colour.
It is important to protect your face with sun screen but to expose as much as your skin as possible, at least without offending anyone! Make sure you never allow your skin to burn. Vitamin D breaks down quite quickly, meaning that stores can run low, especially in winter or areas with lower levels of sunlight.
Vitamin D from foods
Preformed vitamin D can be found in animal products such fatty fish and their liver and egg yolks but even then, only in low levels. There are no natural vegan food sources, (apart from one which we will mention shortly!), however because vitamin D is difficult to obtain via dietary sources many foods are fortified. These include plant milks, fruit juices, cereals, breads nutrition bars and even pastas.
So, what about the one vegan natural source, well its mushrooms. Portobello and Maitake mushrooms have both been found to contain vitamin D when exposed to sunlight. When picked these mushrooms contain very low levels of vitamin D but if they are put in direct sunlight gill side up when freshly picked they actually absorb the vitamin D and can store it for up to a year!
So how much do you need?
As with many vitamins guidelines tend to vary from country to country. The UK guidance is an RDA of 10 micrograms, bear in mind this is a minimum figure to avoid health problems. This may also this be shown as 400 IU, which stand for International Units on some labels. The conversion is 1 microgram to 40 IU so 10 micrograms is equal to 400 IU. In the US the RDA is higher at 15 micrograms or 600 IU.
It is worth noting that taking very high levels of vitamin D supplements may be harmful as it has been known to cause (hypercalcaemia) overly high blood calcium levels. High calcium levels in the blood can lead to weakened bones as well as kidney damage. The guideline for supplementation is to not exceed 100 micrograms per day.
Do I need to supplement?
Other than vitamin B12 we never recommend supplementing “just in case”. We should always try to get our nutrients from natural sources, that being our food or in the case of vitamin D from the sun. However, with such high levels of the population (vegan and non-vegan) vitamin D deficient it is important to get levels checked via a blood test, ideally at least once a year. This can help determine if you need to increase your sun exposure or even add a supplement.
If supplementation is required it is important to check the source. There are two types of vitamin D. Vitamin D2 or ergocalciferol is from plant sources, normally UVB irradiated mushrooms. Vitamin D3 or cholecalciferol can be of animal origin, usually from lanolin in sheep’s wool although there are now vegan sources of vitamin D3 normally sourced from lichen.
The good news is if you do need to supplement there are a range of quality vegan options for both vitamin D2 and vitamin D3. If a high dose is required D3 has been shown to be the preferred option.
The best vegan sources of vitamin D.
Ok so let’s just remind ourselves of the best vegan source of vitamin D. Well it is exactly the same as for non-vegans and it’s the sun! And as for dietary sources we have the option of vitamin D fortified foods. These tend to include plant-based milks, vegetable spread, breakfast cereals and cereal bars. It is always worth checking to make sure that these items are vegan as often they are fortified with the animal derived from of vitamin D.
Then of course there are mushrooms. If you are unable to grow your own or buy almost immediately after they are picked then it is worth knowing that some suppliers have started exposing their mushrooms to UV light to produce ‘vitamin D mushrooms’ which they then market on the packaging. Analysis of 100 grams of these vitamin D mushrooms showed they contained around 9 micrograms of vitamin D.
So if possible try to get at least 15 minutes in the sun 3 times per week. Look to buy foods that are fortified with vitamin D making sure it is from a vegan source. If you can buy fresh mushrooms leave them in direct sunlight for at least 8 hours before consuming, or look for vitamin D mushrooms that have been exposed to UV light. And don’t forget if you’re lucky enough to be able to get sufficient sun to put sunscreen on your face and cover up those bits the neighbours shouldn’t see!