Johnson Mary Ann, Hawthorne Nicole A, Brackett Wimberly R, Fischer Joan G, Gunter Elaine W, Allen Robert H, Stabler Sally P
Department of Foods and Nutrition, University of Georgia, Athens, USA.
Am J Clin Nutr. 2003 Jan;77(1):211-20. doi: 10.1093/ajcn/77.1.211.
The effect of the folate food fortification program on the prevalence of hyperhomocysteinemia in the older population with coexisting vitamin B-12 deficiency is not known.
The objective was to determine the prevalence of hyperhomocysteinemia and vitamin B-12 deficiency in elderly who were using Title IIIc nutrition services, after folate food fortification in the United States.
Demographic, nutritional, cognitive, routine diagnostic, and serum methylmalonic acid (MMA) and total homocysteine (tHcy) tests were performed in a convenience sample of 103 elderly enrolled in nutrition service programs in rural northeast Georgia. A subgroup (n = 27) was treated with vitamin B-12, 2.5 mg, and a multivitamin with 400 micro g folic acid, 2 mg vitamin B-6, and 27 mg ferrous fumarate.
The total cohort included 103 participants (+/- SD age: 76.4 +/- 8.1; 80% female; 68% white, 32% African American). Vitamin B-12 deficiency (serum vitamin B-12 < 258 pmol/L and MMA > 271 nmol/L) was present in 23%. Mean serum folate was high, 39.3 nmol/L, and no subject had serum folate < 6.8 nmol/L. Mean tHcy was 17.6 +/- 7.2 micro mol/L in vitamin B-12-deficient subjects and 10.8 +/- 3.6 micro mol/L in those who were nondeficient. Determinants of high tHcy were vitamin B-12 deficiency, high serum creatinine, and low red blood cell folate. Those with vitamin B-12 deficiency were more likely to have poor cognition (58% compared with 20%, P < 0.001) and anemia (38% compared with 18%, P = 0.042). High-dose oral B-12 therapy lowered mean MMA and tHcy by 49% and 32%, respectively.
Vitamin B-12 deficiency was prevalent and was associated with poor cognition, anemia, and hyperhomocysteinemia.
叶酸食品强化计划对同时存在维生素B-12缺乏的老年人群高同型半胱氨酸血症患病率的影响尚不清楚。
确定在美国进行叶酸食品强化后，使用IIIc类营养服务的老年人中高同型半胱氨酸血症和维生素B-12缺乏的患病率。
对佐治亚州东北部农村地区参加营养服务项目的103名老年人的便利样本进行了人口统计学、营养、认知、常规诊断以及血清甲基丙二酸（MMA）和总同型半胱氨酸（tHcy）检测。一个亚组（n = 27）接受了2.5毫克维生素B-12以及含有400微克叶酸、2毫克维生素B-6和27毫克富马酸亚铁的多种维生素治疗。
整个队列包括103名参与者（年龄±标准差：76.4±8.1岁；80%为女性；68%为白人，32%为非裔美国人）。23%的人存在维生素B-12缺乏（血清维生素B-12<258 pmol/L且MMA>271 nmol/L）。血清叶酸均值较高，为39.3 nmol/L，且无受试者血清叶酸<6.8 nmol/L。维生素B-12缺乏者的平均tHcy为17.6±7.2微摩尔/升，非缺乏者为10.8±3.6微摩尔/升。高tHcy的决定因素是维生素B-12缺乏、血清肌酐升高和红细胞叶酸水平低。维生素B-12缺乏者认知功能差（58%对比20%，P<0.001）和贫血（38%对比18%，P = 0.042）的可能性更大。高剂量口服B-12治疗分别使平均MMA和tHcy降低了49%和32%。
维生素B-12缺乏普遍存在，且与认知功能差、贫血和高同型半胱氨酸血症有关。
