Serum ascorbic acid levels in men aged 55-75 years: association to selected social factors and biochemical parameters.

Serum ascorbic acid (SAA) levels were determined in 500 subjects aged 55-75 years participating in the New Risk Factors (NRF) Survey between March and December 1990. In the total sample mean concentration of SAA was 8.75 mg/1 (95% confidence interval: 8.41-9.20). SAA levels of 2 mg/l or less (severe hypovitaminosis C) were found in 19 subjects (3.8%). A further 9.6% of subjects (n=48) has SAA levels between 2 and 4 mg/l (marginal hypovitaminosis C). Subjects with hypovitaminosis C reported a significantly higher daily cigarette consumption and had higher blood lead (B-Pb) and blood cadmium (B-Cd) levels. An Inverse relationship was found between SAA levels and smoking status, body mass index (BMI) and B-Pb. Among current smokers aged 55-65 years the prevalence of hypovitaminosis C was not significantly higher than in non smokers (chi(2) was 2.4 for severe and 4.7 for marginal hypovitaminosis C, respectively). On the contrary, in subjects aged 66-75 years the occurrence of hypovitaminosis C was significantly higher in smokers than in non-smokers (chi(2) was 6.6 for severe and 10.3 for marginal hypovitaminosis C. respectively).