Vitamin D for vegans: the form problem and how much to take

How much vitamin D, and when

Between about October and March, the sunlight in the UK is too weak for your skin to make vitamin D, whatever the weather does, which is why the advice is seasonal. The NHS suggests adults and children over one consider 10 micrograms a day through those months. Ten micrograms is 400 IU, the same amount written two ways, which is one of the reasons vitamin D confuses people. Some groups are advised to take it all year: those who are rarely outdoors, who cover their skin, or who have darker skin and make less from the sun. None of this is specific to a plant-based diet. Where the diet changes things is the form on the label.

The vegan problem: where D3 usually comes from

This is where the label matters. Vitamin D on a supplement label is usually D3, and most D3 is made from lanolin, the oil in sheep's wool. It is an animal-derived ingredient, which means a lot of ordinary vitamin D3 is not suitable for vegans, even though nothing on the front of the pack says so. The vegan workaround used to be vitamin D2, from plants and fungi, but that comes with a trade-off worth understanding.

D2 versus D3, and why lichen

Vitamin D comes in two forms. D2 comes from plants and fungi and is reliably vegan, but on balance it raises and holds blood levels less effectively than D3. D3 is the form your own skin makes and the one that tends to work better, but the usual source is animal. That left vegans choosing between the better form and a plant source, until lichen. Lichen is a rare plant source of true D3, so a D3 grown from wild-harvested lichen gives you the more reliable form and keeps it fully plant-based. Ours is exactly that. It is the sourcing detail worth checking on any vitamin D you buy as a vegan: if it does not say lichen or specifically vegan D3, assume the D3 is from wool.

How high should you go?

For most people through winter, a modest daily amount does the job, and our 2500 IU lichen D3 is a comfortable everyday dose. You will also see 5000 IU on the shelf. That sits above the level the UK sets as the safe daily maximum for long-term use, which is 100 micrograms or 4000 IU for adults, so it is a deliberate high-dose choice for people who know they run low or who have been advised to take more. It is not where most people should begin. We go through the full dose ladder and the 5000 IU question on the vitamin D3 guide.

Which one to choose

For simple winter cover, the 2500 IU lichen D3 is the easy pick. The 5000 IU is there as a high-dose option if you know you run low or have been advised to take more. And if bones are your main concern, a D3 and K2 combination is worth a look, since the two are often paired for bone support. All of them use D3 from lichen, so they suit a plant-based diet.