Relationship of tobacco smoking with serum vitamin B12, folic acid and haematological indices in healthy adults.

OBJECTIVES To investigate the effects of tobacco smoking on serum vitamin B12, folic acid and haematological parameters in healthy Thai smokers and non-smokers. DESIGN Cross-sectional study of smokers and non-smokers in a military unit in Bangkok, Thailand. SETTING A military unit in Thailand. SUBJECTS One hundred and twenty-three male smokers from a military unit in Bangkok, who participated voluntarily in the study, were investigated. Sixty-six male non-smokers from the same unit were selected as controls. Fasting blood samples were collected for investigation of vitamin B12, folic acid and haematological variables. RESULTS The serum folic acid concentration of smokers was lower than that of non-smokers, but was not statistically significantly different. Haemoglobin was lower in smokers than in non-smokers; 16.3% of smokers were anaemic compared with only 3.0% of non-smokers. Anaemia was not related to folate deficiency. The white blood cell count was found to be higher in smokers than in non-smokers. CONCLUSION The results of this study suggest that there were low serum folic acid concentrations in smokers compared with non-smokers, which might contribute to the development of vascular and cardiovascular diseases. The higher white blood cell count might be indicative alterations in the immune functions of smokers.