I was deficient because of hypothyroidism. My B12 level went up in just two days of consumption. I recommend this to Vegans, vegetarians and even Non vegetarians. Because research says that within the Non-veg population too 60 % of them are deficient in B12. This is a must have for all ages but specially - old people, children, pregnant women and those who have certain health problems. Even one thinks they cannot have this everyday on a regular basis, I recommend that they have it at least one every few months because B12 can be stored in the body, so once optimal levels are reached having it once in a few months should not be bad as well