Plasma ascorbic acid concentrations in the Republic of Karelia, Russia and in North Karelia, Finland.

OBJECTIVES: To determine the plasma ascorbic acid concentrations among men in North Karelia (Finland) and in Pitkäranta (Republic of Karelia) and to test how a short intervention would affect the plasma concentrations.
DESIGN: The baseline survey was done as a cross-sectional population survey. A subsample was selected to the intervention study and randomised to treatment and control groups.
SETTING: North Karelia province in Finland and the Pitkäranta area in the Republic of Karelia.
SUBJECTS: In the cross-section population survey the stratified random sample of men between 25 and 64 years of age was 1000 in North Karelia and 500 in Pitkäranta. Participation rates were 68% and 77%, respectively. Plasma ascorbic acid measurements were made in one-third of the sample. In Pitkäranta 60 men, having very low plasma ascorbic acid concentrations, were invited to the intervention study.
INTERVENTIONS: A controlled intervention study was made with blackcurrant-strawberry nectar in which vitamin C content was approximately 70 mg/100 g. The treatment group drank two times daily 200 ml nectar for 4-5 weeks. After intervention plasma ascorbic acid concentration was measured from both treatment and control groups.
RESULTS: Plasma ascorbic acid concentrations were very different in the two areas. In Pitkäranta 93% of the men and in North Karelia only 2% of the men had plasma levels suggesting severe vitamin C deficiency. After intervention 46% of the men in the experimental group compared with 5% in the control group had plasma ascorbic acid concentrations exceeding 23 mumol/l (4.0 mg/l).
CONCLUSIONS: In addition to a high smoking prevalence the very low ascorbic acid concentration among men in the Republic Karelia can have an effect on the high cardiovascular disease mortality.

RCT Entities:   Population Interventions Outcomes