I don't know if there is any side effects but if i were he I would take them from the food, it is a better way to keep living fit and healthy to đ
Hypervitaminosis is not really a big deal, however he must be careful on the doses because excess of certain vitamins can carry up other conditions
water soluble vitamin toxicity is not seen excess vitamins are excreted in urine thus its completely harmless and there are no side effects