Muscle Soreness, Exercise Injuries and Vitamin D

When doctors don't know the cause of a patient's problem, they often give it a fancy name so you will believe they are giving you a useful diagnosis. A perfect example of this is "idiopathic inflammatory myopathy", which means you have chronic muscle soreness and your doctor doesn't know why. Researchers recently reviewed the effects of exercise on people with chronic muscle soreness and found that exercise is beneficial (Current Opinion in Rheumatology, 04/07/09):
• The muscles of many of subjects with this condition did not get a sufficient oxygen supply
• Exercise increases endurance-type fibers after a 12-week exercise program
• Creatine supplements plus an exercise program are more beneficial than exercise alone
• Intensive resistance training improves muscle strength and endurance
• Exercise reduces muscle soreness and possibly even muscle inflammation

I am now convinced that a leading cause of muscle soreness and slow-healing injuries is lack of vitamin D. All my life, I have suffered a series of baffling injures that usually occur in the winter and heal in the summer. For the entire winter of 2007-8, I was unable to exercise because of a non-healing hamstring injury and diffuse muscle soreness. Eventually I found that my vitamin D 3 level was 22 nmol/L (normal is greater than 75). I took the prescribed treatment of 50,000 IU of vitamin D twice a week and my muscles became so sore that I couldn't even walk. In the summer, the hamstring injury healed and the soreness disappeared. This winter I went to Florida and was able to train on my bicycle better than ever. In March I went back to wintery Maryland and the non-healing hamstring injury and soreness reappeared. This time I improved within 24 hours of taking 2000 IU of vitamin D twice a day. From my experience, I conclude that:
• my muscle soreness and non-healing injuries are caused by or worsened by low levels of vitamin D
• very high doses (50,000 IU) may increase muscle soreness
• lower doses of vitamin D (2000 to 4000/day) or daily sunlight exposure cured my muscle soreness and helped to heal my injuries

Dr. John Cannell of the Vitamin D Council quotes 14 studies that show that athletic performance improves in the summer months when sunshine is abundant, or with ultraviolet light exposure in winter.

If your muscles feel sore or you keep on being injured when you exercise, get a blood test called D3. If it is below 75 nmol/L, your problems may be caused by lack of vitamin D and be cured by getting some sunshine or taking at least 2000 IU each day of the very inexpensive vitamin D3.