A new study has found that children who spend less time in the sun are more likely to develop asthma, allergies and even eczema.
Researchers at The Telethon Kids Institute in Perth said: "Vitamin D can help to promote tolerance to allergens.
"That means our immune system can ignore things that are harmless to it. When we get allergies is when our immune system has a response to something that it should just ignore."
The first two years of a child's life is a crucial time for allergies and chest infections to turn into something worse.
Kidspot spoke to Dr Sam Hay and she explained how the new Vitamin D findings work.
"We have known about its importance with bone strength for some time now, but this new research is shedding more light (pun intended) on other roles for Vitamin D in the body.
"This research shows Vitamin D plays an important part in immune system regulation."
Dr Hay continues: "This study has shown that when Vitamin D levels are low in early childhood years, then there is a greater risk of asthma, as well as allergy and eczema, once kids are 10 years old.
"Plus, babies deficient in Vitamin D have harmful bacteria in their upper airways at alarming levels."
However, don't worry if you think you need to leg it out of the house and buy Vitamin D supplements, all you need to do is spend more time in the sun with your kids. Whether it's a walk around your local park, a trip to the shops or a short bike ride!
Dr Hay thinks it's all about balance: “It’s frustrating, because on one hand we are told to cover kids up to avoid early skin damage from the sun, yet now we are told to put them in the sun!
"I think it’s about the balance, a total of about 20 minutes a day is all that’s needed to get enough Vitamin D," she added.