A new study says breastfed children eating solid foods still may not be getting adequate amounts of vitamin D.

Credit: Frederic Cirou/Getty Images

Breast is best, but maybe not when it comes to providing baby with an adequate supply of vitamin D.

A new study published in the American Journal of Public Health advises moms to supplement breastfed children's diets with the nutrient. That's right; it may not be enough if you are taking a D vitamin while breastfeeding. It may not even be enough if your baby is starting to eat solid food.

Researchers looked at more than 2,500 children who were breastfed for up to three years, but also ate solid food. Kids who did not take a D supplement were more at risk for developing a deficiency. Those who were breastfed for up to 24 months had a 16 percent risk of low levels, and the risk increased to 29 percent by 36 months of being breastfed.

What's the big deal with Vitamin D? Babies and toddlers who don't get enough may not adequately absorb calcium, which puts the child at risk for developing rickets or for the bones to bow. Kids are also more likely to be fatigued, and it can even lead to impaired immune function.

It's worth mentioning the AAP recommends both breastfed and formula-fed babies take vitamin D supplements for the first year of life, something I found very interesting.

Lead researcher Dr. Sarah Ronis told ABC News parents should take away from the study that kids who are breastfed longer and are not taking a supplement are likely not getting "sufficient intake from other sources."

Ronis stressed that breast milk is still best for baby with proper supplementation. Children can stop taking a supplement when they drink at least 32 ounces of baby formula or regular milk, which should provide enough vitamin D.

Given this new information, I would definitely ask my pediatrician about supplementation to decide what was best for my child if I were still breastfeeding. I'd also be sure to ask if giving him a multivitamin was okay, or if a separate D vitamin was needed.

What's your reaction to this study?

Melissa Willets is a writer/blogger and a mom. Follow her on Twitter (@Spitupnsuburbs), where she chronicles her love of exercising and drinking coffee, but never simultaneously.