Serum vitamin A and zinc levels of healthy people in northeast Thailand.

Background: Vitamin A and zinc are micronutrients which co-related to diseases afflicting northeast Thais. Vitamin A and zinc concentrations in serum have been studied in healthy northeast Thais between 23 and 75 years.

Methods: Vitamin A was analyzed by HPLC and zinc was determined by flame atomic absorption spectrometry.

Results: The average serum vitamin A level of the population (n=744) was 2.30 micromol/l (95% CI=2.25-2.35). Males had significantly higher vitamin A levels than females, i.e. 2.61 micromol/l (95% CI=2.53-2.68) vs. 2.03 micromol/l (95% CI=1.98-2.09) (p<0.0001). The vitamin A level of females tended to increase significantly with age (p<0.005), whereas in males levels were relatively constant throughout the age range studied. The average serum zinc level of the population (n=1113) was 18.20 micromol/l (95% CI=18.05-18.36). There was no significant difference in the zinc levels between males and females, i.e. 18.20 micromol/l (95% CI=17.90-18.36) vs. 18.36 micromol/l (95% CI=18.05-18.66). The zinc level tended to decrease significantly as age increased, particularly in the male population (p<0.05).

Conclusion: The results from this study provide baseline data of serum vitamin A and zinc levels in healthy northeast Thais.