The epidemic of vitamin D deficiency

A 37-year-old woman was referred to our endocrine clinic for management of her long-standing hypothyroidism. Her main complaints were muscle aches and pains that started about a year ago. The symptoms progressed to generalized muscle weakness. She described difficulty in getting out of her chair and in climbing stairs. She had an extensive work-up done by her neurologist and rheumatologist, including nerve-conduction studies and a muscle biopsy. The evaluation was normal, and she was diagnosed with fibromyalgia. She had gastric bypass surgery in 1998 and lost 150 pounds since the operation. She also has had lactose intolerance and a compression fracture without trauma. Her weight was 314 pounds. She had proximal muscle weakness. The rest of her physical examination was normal. Serum laboratory values are listed in Table 1. Based on the laboratory values, she was diagnosed as having severe vitamin D deficiency. She was started on 50,000 IU of vitamin D2 (Ergocalciferol) once a week for 6 months. Now her 25 hydroxyvitamin D level is 40 ng/mL, and her muscle strength has improved.