Pediatric formulations of iron with folic acid, multivitamins, and calcium with vitamin D3 are generally safe and commonly prescribed for a 1.5-year-old to support healthy growth. However, because a toddler's nutritional needs are unique, the exact dosages must be precisely calculated by your pediatrician based on his specific weight and dietary intake. Giving excess iron or calcium can cause mild digestive upset. Please consult your pediatrician before starting these; they can evaluate his specific nutritional needs, recommend the most appropriate pediatric-strength alternatives, and prescribe the exact, safe dosages tailored specifically for him.