Endocrinologists at the University at Buffalo suggest that adults afflicted with incapacitating muscle weakness and pain may be suffering from an easily treatable vitamin D deficiency. A report by Paresh Dandona, M.D. in the Archives of Internal Medicine (April 24, 2000) reported that five patients confined to wheelchairs because of severe muscle weakness regained normal muscle strength after four to six weeks of vitamin D supplementation.

This study was the first to describe cases of severe myopathy due to a lack of vitamin D in the United States.

Vitamin D is produced by the liver in the presence of sufficient calcium and sunlight.

Dandona, a native of India and educated in the United Kingdom, said that individuals who have limited exposure to the sun are particularly vulnerable to this condition. "In addition to osteomalacia (softening of the bones), myopathy is a well-recognized feature of this condition.”

"In the United States, vitamin D deficiency has only recently been appreciated, especially in the northern areas bordering Canada. We see vitamin D deficiency in the hospital setting and in the community at large during the winter months, but in this country, there are no reports of incapacitating muscle weakness associated with vitamin D deficiency."

In each of his cases, the weakness had been attributed previously to other causes: old age, problems associated with diabetes, and general debility. "The diagnosis in these cases was either masked by the presence of neurological disease or had been totally unrecognized because of its insidious onset," said Dr. Dandona. Tests revealed vitamin D deficiency in all five patients. After vitamin D replacement therapy, four patients regained normal muscle strength and were able to walk without support. The fifth -- the patient with anorexia nervosa -- was able to stop using a wheelchair and walk with support.

Dr. Dandona listed the following situations that should raise suspicions about a severe vitamin D deficiency:

• limited sunlight exposure, due to climate or limited sun exposure
• Body aches and pains, especially in the shins and ribs
• Impaired absorption of nutrients