How do I know if my child has vitamin b12 and vitamin D3 deficiency. Also my son only eats indian vegetarian food like sabzi, dal, roti and rice and milk. He does not eat any fruit, not even banana. Doesn't even eat fast food like burger pizza etc. Only sometimes he has started eating chocolate now. I think in vegetarians have this deficiency. Should we give vitamin supplement to 7 year old boy ? Please advise.