Kids and teens who are picky eaters or don’t eat a variety of foods often don’t get enough iron, zinc, or vitamin D, which are important tiny nutrients in food.

Teens and kids with early gray hair tend to have lower levels of certain nutrients like copper, zinc, and vitamin B12 in their blood than other kids their age, but how gray their hair is doesn’t seem to match how low those nutrient levels are.

Kids who are picky eaters often don’t get enough zinc and iron, and that might make them less active and slower to grow or learn.

Kids under 7 are more likely to not have enough iron in their bodies than any other group of people.