I would like to know if one can take supplements such as vitamins and herbal extracts that are vegan certified but not necessarily kosher certified if a similar product in terms of either potency, quality or proper dosage can’t be found kosher,(ex; I only found a vegan soy free version of a vitamin as chewable flavored tablets at the correct dosage and i could only find the same vitamin (k2)Kosher but at a much lower dosage and which contains soy) and for whom would this be considered an issue; meaning, who is really considered sick (a cancer patient versus someone who is not deathly ill but has genetic health issues or who has developed a health condition that must be treated or else it would lead to severe damage and possibly other severe health issues. Also, in which category would one who is considered generally healthy but taking supplements to prevent illness or someone trying to prevent recurrent illness fall?
All vitamins and supplements should ideally have kosher certification. When they are not available, in the form of pills which are swallowed and have no taste and are not edible, one may take without certification. This is even for a healthy person taking supplements. Chewables, liquid or powder which are flavored and edible requires kosher certification as they are like eating food. When there is no alternative, for someone who has a life threatening illness all necessary pills may be taken. Otherwise, they should be avoided. Often you can consult with a Rav who is knowledgeable in these matters who can check if there are kosher sensitive ingredients in the product.