Gosh it is good to hear someone else talk about this vitamin d deficiency issue. i was just diagnosed with that and prscribed 50,000 of vitamin day once a week. I have been living with these symptoms for so long and had on idea what was wrong with me. I m 58 years old also. I truly hopes this helps some of the fatigue and muscle pain that I have been having. Hope it works for you too! Good luck!