What diet should a 16-year-old take as a vegetarian in order to be fit?

Yes, it can if you're not careful. Exercises that involve heavy lifting or high impact can put extra stress on your spine and make the condition worse. However, gentle exercises like walking, swimming, or stretching can actually help relieve pressure on your disc and strengthen the muscles around it....

there is no supplement. just make sure you eat healthy. and why have you not introduced weaning for your child yet? are you feeding your child any other food items?

For any age group a balanced diet is a must. Most people try to look for alterantes for the source of protien which can be replaced by pulses or soya. Also try to add fruits to your diet as well.