I'm a healthy active 71 year old woman who's been on 50mcg levothyroxine for at least 10 years. The blood test numbers always show normal, but I feel cold much of the time, tired, bloated, depressed, with muscle aches and joint pain. I'm not sure how much of this can be attributable to normal aging. I eat a high fiber diet, including walnuts and soy products, which can inhibit the absorption of the drug. Is it possible my dosage needs to be increased? I will contact my doctor, but first want another opinion.