I read recently that yeast devours B vitamins. I had influenza iin 1998, for the first time in 35 years, and the C didn't help me one bit. But the last time I had a cold was September 1985. I wouldn't make a habit of taking this much zinc, but for two or three days there's no danger of toxicity. Up to 1,200 is ok, and useful if you have restless legs or leg cramps.
Some people find Vitamin E helpful in achieving deeper sleep and take it at bedtime.
Our well water has no minerals at all, which can lead to serious health problems. We supplement this way. Also good for pain, especially leg cramps. The recommended ratio of calcium to magnesium is 2 or 2.5 to 1. This antioxidant is an essential component of the mitochondria, the energy producing unit of the cells.