維他命B12

研究概述

• 幫助保持認知和神經系統健康
  維他命B12有助於記憶和調節神經系統。^[1] 缺乏維他命B12會引起胃部的多種吸收問題。^[2] [3] 其中包括自身免疫性惡性貧血（一種自身免疫性疾病，會影響您的胃，導致其攻擊胃中的細胞，產生與維他命B12結合的蛋白質，使您的身體無法再吸收維他命B12）、^{[4] [5]}慢性胰腺炎（胰腺發炎，最終導致結構破壞，阻止身體自然產生胰島素腺）、^{[6] [7]}消化不良、腹腔疾病（一種自身免疫性疾病，攝入麵筋會導緻小腸受損）和克羅恩氏病（一種炎症性腸病， 會影響從嘴到肛門的胃腸道的任何部分）。^{[8] [9]} 這是由於在消化過程中，肉製品解離B12的能力降低。  

  說明性研究

  在一項於2006年歷時兩年的研究中，測試東歐老年人在服用維他命B12和血清葉酸前和後的認知能力，口語流利度和字母搜索能力，亦找出其對人類認知能力的影響。結果顯示，維他命B12水平與口語流利度和單詞回憶的得分呈正比關係。^[10] 另一項針對年齡在72至83歲之組別的研究，顯示缺乏維他命會導致對光、觸覺的不敏感性增強，並導致神經狀況惡化。^[11]     研究評分： 可靠
• 可增加新陳代謝
  有初步證據顯示，維他命B12可通過增加氧化代謝來減輕壓力和炎症。氧化代謝是人體利用氧氣將碳水化合物轉化為能量的過程，這可以增加能量存儲並允許神經衝動更快地運動。^[12]   研究評分： 看好
• 建議素食者、純素食者和老年人服用
  許多素食者和純素食者缺乏維他命B12，因為維他命B12僅存在於動物產品中，而不存在於植物或穀物產品。^{[13] [14] [15]} 隨著年齡的增長，他們吸收維他命B12的難度變得越來越大，維他命B12與蛋白質結合併，且可能難以消化。   研究評分： 可靠
• 參考文獻
  1. Screening for vitamin B-12 and folate deficiency in older persons, Robert Clarke  Helga Refsum  Jacqueline Birks  John Grimley Evans  Carole Johnston  Paul Sherliker  Per M Ueland Joern Schneede  Joseph McPartlin  Ebba Nexo  John M Scott, The American Journal of Clinical Nutrition, Volume 77, Issue 5, 1 May 2003, Pages 1241–1247 2. Green PH, et al. Mechanisms underlying celiac disease and its neurologic manifestations . Cell Mol Life Sci. (2005) 3. Lambert D, et al. Crohn's disease and vitamin B12 metabolism . Dig Dis Sci. (1996) 4. Andres E, Serraj K. Optimal management of pernicious anemia . J Blood Med. (2012) 5. Screening for vitamin B-12 and folate deficiency in older persons, Robert Clarke  Helga Refsum  Jacqueline Birks  John Grimley Evans  Carole Johnston  Paul Sherliker  Per M Ueland Joern Schneede  Joseph McPartlin  Ebba Nexo  John M Scott, The American Journal of Clinical Nutrition, Volume 77, Issue 5, 1 May 2003, Pages 1241–1247 6. Glasbrenner B, et al. Vitamin B12 and folic acid deficiency in chronic pancreatitis: a relevant disorder . Klin Wochenschr. (1991) 7. Girish BN, et al. Chronic pancreatitis is associated with hyperhomocysteinemia and derangements in transsulfuration and transmethylation pathways . Pancreas. (2010) 8. O'Leary F, Samman S. Vitamin B12 in health and disease . Nutrients. (2010) 9. Dali-Youcef N, Andrès E. An update on cobalamin deficiency in adults . QJM. (2009) 10. Serum folate, vitamin B-12 and cognitive function in middle and older age: The HAPIEE study. Horvat P, Gardiner J, Kubinova R, Pajak A, Tamosiunas A, Schöttker B, Pikhart H, Peasey A, Jansen E, Bobak M., Experimental gerontology, 2016 11. Relationship between vitamin B12 and sensory and motor peripheral nerve function in older adults. Leishear K, Boudreau RM, Studenski SA, Ferrucci L, Rosano C, de Rekeneire N, Houston DK, Kritchevsky SB, Schwartz AV, Vinik AI, Hogervorst E, Yaffe K, Harris TB, Newman AB, Strotmeyer ES; Health, Aging and Body Composition Study., Journal of the American Geriatrics Society, 2012 12. The Effect of a High-Dose Vitamin B Multivitamin Supplement on the Relationship between Brain Metabolism and Blood Biomarkers of Oxidative Stress: A Randomized Control Trial., Ford TC, Downey LA, Simpson T, McPhee G, Oliver C, Stough C. https://tinyurl.com/y27orhxs (accessed 20 March 2019) 13. Health effects of vegan diets, Winston J Craig, The American Journal of Clinical Nutrition, 2009 14. Nutritional Update for Physicians: Plant-Based Diets, Tuso PJ, Ismail MH, Ha BP, Bartolotto C., The Permanente Journal, 2013 15. Vitamin B12 - Dietary Supplement Fact Sheet, Office of dietary supplements, National Institutes of Health, 2016