Is 400iu enough?
It is the modest everyday strength referred to in UK guidance for autumn and winter. If you have been told your level is low, your GP will advise on more.
What is the difference between D2 and D3?
D3 is what your skin produces in sunlight, and the body uses it more readily. D2 comes from plant sources.
Is there a vegan version?
Yes – lichen-derived vegan D3, and an organic vegan D2. Ordinary D3 comes from sheep's wool.
Can I give this to a child?
Amounts differ for children and there are products specified for them. Ask a pharmacist rather than dividing an adult product.