Can I give a supplement to my three year old girl who always falls sick when the season change?

Perhaps you can increase her Vitamin D intake as it regulates and strengthens the immune system. I stopped taking my vitamin D tablets a few months ago and I felt the effects almost immediately. I was always tired and I caught cold a few times within the few months I stopped taking Vitamin D. I'm back to regular intake and I have not fallen sick since. You can purchase multivitamins or get chewable Vitamin D tablets for kids separately from pharmacies or iherb.com.