my 10 year old son is a vegetarian, no meat, no egg, and eats a lot of junk food. I was worried about his growth so i ordered this protein supplement, which says it can be used for upraising dietry protein (its not whey, its a mixture of different forms of protein - "musashi Hybrid 92"). But the instruction says its "not suitable for kids under 15.... seek a doctor for 'dietry supervision'"...Is it safe for him??