Can confirm anecdotally. I used to get 2-3 colds a year for about 15 years straight, especially during season changes when the humidity levels changed. Started

Can confirm anecdotally. I used to get 2-3 colds a year for about 15 years straight, especially during season changes when the humidity levels changed. Started taking 5000 IU vitamin D3 daily about 2 years ago and I haven't gotten sick since.