My wife and I are in our seventies, and both of us started taking Daily Immunity Booster many years ago. It has made a big difference in our life. One time, about 20 years ago, I quit taking it to see how this affected me. Two weeks later I started losing my energy. So I began taking it again. Then, about five years ago, I quit for a month and took another product. The same thing happened again. I started losing my energy, and I again started taking Daily Immunity Booster.