As winter approaches, it’s time to start boosting your immune system with supplements so it’s better equipped to fight off colds, flu and other seasonal illnesses. To do that, a nutritionist recommends adding five key vitamins and minerals to your daily routine, which should be taken alongside a healthy, nutritious diet. 5 winter supplements to start taking “The key to maintaining a strong immune system during flu season is to start early,” Kyle Crowley, a nutritionist at Protein Works says. “Preparing your body before the cold weather hits can help you build up defences.” He suggests taking t…