Cold season is upon us. Vitamin D levels are down. People are cloistered indoors. Kids are walking petri dishes. Drug stores are advertising free flu shots. It’s that time of year. I’m sure a few of you are even sniffling as you read this, or maybe trying to ignore the pain of swallowing with a sore throat. Colds seem like an inevitability, maybe not so much since you’ve cleaned up your diet, but nothing is 100% fool-proof. You will get…