A 15-year-old girl is brought to the office by her parents for a wellness visit. The patient is up to date on recommended vaccinations and does not use tobacco, alcohol, or illicit drugs. She is at the 30th percentile for height and weight and achieved normal developmental milestones throughout childhood. The patient and her family live on a farm in rural Vermont. They recently started following a vegan diet with exclusive consumption of unprocessed, locally produced foods, including a variety of fruits, vegetables, grains, legumes, and nuts, and strictly avoiding all animal-based products. Physical examination is normal. This patient's diet places her at increased risk for deficiency for which of the following nutrients?

Question

Quizplus · Accepted Answer

Explanation: 11ec25c8_d5fa_4bdb_bc81_3536f81c4423_MD0003_00 This patient has adopted a vegan diet, a common dietary pattern characterized by abstinence from all animal-sourced products. It differs from a simple vegetarian diet in that vegetarians typically consume some nonmeat animal products (eg, milk, gelatin, eggs). A patient on a vegan diet is therefore dependent completely on plant-based products and supplements for dietary requirements. Dietary vitamin D and calcium are obtained primarily from dairy and other animal-derived products. Vitamin D is also generated in the skin due to sunlight exposure (ie, conversion of 7-dehydrocholesterol to cholecalciferol); however, this accounts for only about half of the daily requirement (~200-400 IU/day of a requirement of 600 IU/day), often less in northern latitudes (eg, Vermont). Supplementation may be needed to reduce the risk of osteoporosis. Cobalamin (vitamin B₁₂) deficiency can also occur, leading to megaloblastic anemia and subacute combined degeneration of the dorsal columns of the spinal cord. Although many plant products (eg, leafy green vegetables) provide iron, the quantity may not be adequate for individuals with increased iron requirements (eg, growing children, menstruating women). Many processed foods intended for vegan consumers are fortified with nutrients commonly deficient in a vegan diet (eg, vitamin D in soy milk and other dairy substitutes). However, this patient is avoiding processed foods and should be counseled to supplement calcium, vitamin D, vitamin B₁₂, and iron (Choice A). ₁₂ (Choices C, D, and E) Unlike meat, most vegan foods are not a source of complete protein and may expose patients to deficiencies of essential amino acids. However, soy is a complete protein source, and patients can also obtain all the essential amino acids from a blended protein source (eg, grains plus legumes). Also, folic acid is widely available in plant products and not commonly deficient in a vegan diet. Educational objective: A vegan diet is characterized by abstinence from all animal-sourced products. Calcium, vitamin D, vitamin B₁₂, and iron are commonly deficient in a vegan diet and may require supplementation. ₁₂

A 15-Year-Old Girl Is Brought to the Office by Her