Clinical Pearls & Morning Reports
Published July 18, 2018
There is only one cause of slowly progressive fatigue on exertion and weakness that responds within days to vitamin supplementation, and that is scurvy, a condition caused by vitamin C (ascorbic acid) deficiency. Read the latest Case Records of the Massachusetts General Hospital here.
Q: Is vitamin C an essential nutrient?
A: In contrast with most other mammals, humans do not synthesize vitamin C, an essential nutrient that is necessary for many enzymatic reactions in its role as an electron donor and is critical in the synthesis of catecholamines.
Q: How common is vitamin C deficiency in the United States?
A: Vitamin C is present in many fruits and vegetables, but proper food preparation is necessary to avoid degrading the vitamin C content. Some men are at risk for the development of “bachelor scurvy,” a condition that occurs among unpartnered men who prepare their own meals or eat out frequently, drink heavily, and eat virtually no fruits or vegetables. The third National Health and Nutrition Examination Survey estimated that 14% of men and 10% of women in the United States have vitamin C deficiency.
A: Impaired collagen synthesis is a hallmark of scurvy. Orthostatic hypotension, bruising, gingival bleeding with loss of teeth, progressive fatigue, and rapid reversal of weakness after the initiation of multivitamin supplementation are all consistent with the diagnosis of scurvy. In vitro experiments have shown that vitamin C binds to the alpha-adrenergic receptor, enhancing its activation by epinephrine. Vasomotor instability with shock is thought to be one of the primary causes of sudden death in patients with scurvy. Scurvy has not been associated with peripheral neuropathy.
A: After bariatric surgery, the most common deficiencies are in calcium, vitamin B12, vitamin D, and iron, and the least common deficiencies are in vitamin B1 (thiamine), copper, and zinc. When evaluating a patient who has undergone bariatric surgery, the clinician would note the type of procedure, since the associated vitamin and micronutrient deficiencies vary according to procedure type. For example, copper deficiency occurs in 10 to 20% of patients who have undergone Roux-en-Y gastric bypass, but there is only one case report of copper deficiency occurring after sleeve gastrectomy.