title: [Serum folate and vitamin B12 in older people: results from the Chilean National Health Survey 2009-2010].
abstract: BACKGROUND
  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.
  
  
  OBJECTIVE
  To describe and analyze SF and B12 levels in older Chileans and to identify risk groups.
  
  
  METHODS
  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.
  
  
  RESULTS
  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.
  
  
  CONCLUSIONS
  Folate deficit is almost inexistent, but a significant percentage of participants had SFL suggesting the need for revising the current wheat flour fortification levels.
authors: Cecilia
authors: C
authors: Castillo-Lancellotti
authors: Paula
authors: P
authors: Margozzini
authors: Gonzalo
authors: G
authors: Valdivia
authors: Oslando
authors: O
authors: Padilla
authors: Ricardo
authors: R
authors: Uauy
authors: Jaime
authors: J
authors: Rozowski
authors: Josep A
authors: JA
authors: Tur
mesh_terms: D000368:Aged; D002677:Chile / Q000453:epidemiology; D005260:Female; D005492:Folic Acid / Q000097:blood*; D005494:Folic Acid Deficiency / Q000097:blood* / Q000453:epidemiology; D006306:Health Surveys; D006801:Humans; D008297:Male; D008875:Middle Aged; D016017:Odds Ratio; D011159:Population Surveillance; D015995:Prevalence; D012307:Risk Factors; D014806:Vitamin B 12 Deficiency / Q000097:blood* / Q000453:epidemiology
chemical_list: D005492:Folic Acid