Institute of Food, Nutrition and Human Health, Massey University, Auckland, New Zealand.
Nutrition. 2012 Jan;28(1):20-4. doi: 10.1016/j.nut.2011.05.006. Epub 2011 Aug 11.
Asian Indians are an at-risk group for vitamin B12 deficiency (because of vegetarianism) and insulin resistance (IR). Vegetarianism and consequent vitamin B12 deficiency may be associated with IR. This study aimed to describe the vitamin B12 status of predominantly overweight/obese women of South Asian origin living in Auckland and to correlate serum vitamin B12 and vegetarian status with IR as part of the larger Surya Study looking at health and lifestyle in this population.
This was a cross-sectional study of 135 women at least 20 y of age who were not taking vitamin B supplements or medications that could affect vitamin B12 concentrations (serum vitamin B12 < 800 pmol/L). Data collection included serum vitamin B12, serum folate, measurements of IR (HOMA2-IR), and anthropometry. Vegetarian status was established for 124 subjects (90 non-vegetarians, 34 vegetarians).
Mean serum vitamin B12 was 227 pmol/L (95% confidence interval 210-245), serum folate was 19.1 nmol/L (18.0-20.2), and HOMA2-IR was 1.24 (1.13-1.36). Non-vegetarians had higher serum vitamin B12 levels (257 pmol/L, 235-281) than vegetarians (181 pmol/L, 159-207), P < 0.001. Vitamin B12 deficiency (<150 pmol/L) in vegetarians was 24% versus 9% in non-vegetarians. Non-vegetarians had increased body mass index (25.9 kg/m², 25.0-26.9, versus 23.9 kg/m², 22.6-25.3), waist circumference (81 ± 10.1 versus 75.8 ± 9.88 cm), and HOMA2-IR levels (1.30, 1.17-1.46, versus 1.00, 0.83-1.22). No correlation was found between serum vitamin B12 and HOMA2-IR. A significant positive correlation between non-vegetarian status and IR disappeared after controlling for body mass index.
This study population has a low serum vitamin B12 status, especially if vegetarian. The high rates of observed obesity may have overshadowed any other contributing factor to IR.
亚洲裔印度人是维生素 B12 缺乏症（由于素食主义）和胰岛素抵抗（IR）的高危人群。素食主义和随之而来的维生素 B12 缺乏症可能与 IR 有关。本研究旨在描述居住在奥克兰的南亚裔超重/肥胖女性的维生素 B12 状况，并将血清维生素 B12 和素食状况与 IR 相关联，作为更大的 Surya 研究的一部分，该研究旨在研究该人群的健康和生活方式。
这是一项横断面研究，共纳入了 135 名年龄至少 20 岁的女性，她们没有服用维生素 B 补充剂或可能影响维生素 B12 浓度的药物（血清维生素 B12 <800 pmol/L）。数据收集包括血清维生素 B12、血清叶酸、IR（HOMA2-IR）测量和人体测量学。对 124 名受试者（90 名非素食者，34 名素食者）确定了素食状况。
平均血清维生素 B12 为 227 pmol/L（95%置信区间 210-245），血清叶酸为 19.1 nmol/L（18.0-20.2），HOMA2-IR 为 1.24（1.13-1.36）。非素食者的血清维生素 B12 水平（257 pmol/L，235-281）高于素食者（181 pmol/L，159-207），P < 0.001。素食者的维生素 B12 缺乏症（<150 pmol/L）为 24%，而非素食者为 9%。非素食者的体重指数（25.9 kg/m²，25.0-26.9，与 23.9 kg/m²，22.6-25.3）、腰围（81 ± 10.1 与 75.8 ± 9.88 cm）和 HOMA2-IR 水平（1.30，1.17-1.46，与 1.00，0.83-1.22）更高。血清维生素 B12 与 HOMA2-IR 之间未发现相关性。在控制体重指数后，非素食状态与 IR 之间的显著正相关关系消失了。
本研究人群的血清维生素 B12 水平较低，尤其是素食者。观察到的肥胖率较高可能掩盖了任何其他与 IR 相关的因素。
