Castillo-Lancellotti Cecilia, Margozzini Paula, Valdivia Gonzalo, Padilla Oslando, Uauy Ricardo, Rozowski Jaime, Tur Josep A
Rev Med Chil. 2013 Sep;141(9):1107-16. doi: 10.4067/S0034-98872013000900002.
Supraphysiological levels (SFL) of serum folate (SF) derived from flour fortification with folic acid (FA) could be risky among older adults with low vitamin B12 (B12) levels.
To describe and analyze SF and B12 levels in older Chileans and to identify risk groups.
Participants were 1.043 older people aged ≥ 65 years from the National Health Chilean Health Survey 2009-2010 (ChNHS 2009-10), a multistage stratified random sample, representative of the national population. SF (µg/L) and B12 (pg/ml) were determined in fasting samples by competitive chemoluminescence immunoassay. Mean, deciles and percentiles 5 and 95th were calculated. We defined SF categories: < 4.4 (deficit); 4.41-20 (normal) and SFL: 20.01-25.6; 25.6-29 and > 29 µg/L (80th percentile of the distribution) and vitamin B12 categories: ≤ 200 (deficit); 200.1-299.5 (marginal deficit) and > 299.5 (normal). Prevalence rates, multiple and logistic regression models were used and adjusted by sex and age, educational level and residence area.
SF and B12 mean and 95th percentiles were 21.2 ± 0.56/38.6 µg/L and 348.4 ± 7.6/637(pg/ml) respectively. Forty nine percent of participants had SFL. Folate and B12 deficiency were present in 0.3 and 8.1% of participants, respectively. Men had significantly lower prevalence of SFL > 29 µg/L (OR adjusted odds ratio 0.47 95% confidence intervals: 0.26-0.84). B12 showed no significant variation by age and sex. The prevalence of SFL associated with B12 deficiency was 4.1%. No statistically significant association was observed between levels of folate and B12.
Folate deficit is almost inexistent, but a significant percentage of participants had SFL suggesting the need for revising the current wheat flour fortification levels.
通过在面粉中添加叶酸（FA）使血清叶酸（SF）达到超生理水平（SFL），对于维生素B12（B12）水平较低的老年人可能存在风险。
描述和分析智利老年人的SF和B12水平，并确定风险群体。
研究对象为来自2009 - 2010年智利国家健康调查（ChNHS 2009 - 10）的1043名年龄≥65岁的老年人，这是一个多阶段分层随机样本，代表全国人口。通过竞争性化学发光免疫分析法测定空腹样本中的SF（μg/L）和B12（pg/ml）。计算均值、十分位数以及第5和第95百分位数。我们定义SF类别：<4.4（缺乏）；4.41 - 20（正常）以及SFL：20.01 - 25.6；25.6 - 29和>29μg/L（分布的第80百分位数），以及维生素B12类别：≤200（缺乏）；200.1 - 299.5（边缘缺乏）和>299.5（正常）。使用患病率、多元和逻辑回归模型，并按性别、年龄、教育水平和居住地区进行调整。
SF和B12的均值及第95百分位数分别为21.2±0.56/38.6μg/L和348.4±7.6/637（pg/ml）。49%的参与者存在SFL。叶酸和B12缺乏分别出现在0.3%和8.1%的参与者中。男性中SFL>29μg/L的患病率显著较低（调整后的比值比0.47，95%置信区间：0.26 - 0.84）。B12在年龄和性别方面无显著差异。与B12缺乏相关的SFL患病率为4.1%。未观察到叶酸和B12水平之间存在统计学上的显著关联。
叶酸缺乏几乎不存在，但相当比例的参与者存在SFL，这表明需要重新审视当前小麦粉的强化水平。
