The habit of smoking has been shown to cause a vitamin B12 deficiency, as a result of a study in Thailand. This study was done by researchers at the University of Mahidol in Bangkok, Thailand.
The country of Thailand was well-suited for this study since it is estimated that 23% of the 52 million people residing there are smokers. This is unfortunate as smoking has been linked to respiratory illnesses, heart disease, strokes and higher mortality rates. The components of cigarettes are to blame. Besides nicotine, there are hundreds of chemical compounds in cigarettes that cause these illnesses.
Vitamin B12 is necessary to help the body break down a toxic amino acid, known as homocysteine. High blood levels of homocysteine lead to plaque buildup in the arteries, which causes heart disease and strokes. These high levels of homocysteine are usually indicative of a vitamin B12 deficiency. For purposes of this study, homocysteine blood concentrations of the volunteers were measured, in addition to vitamin B12 blood plasma levels.
Scientists at the Unversity of Haidol enlisted a total of 271 healthy men between the ages of 19 and 62 years old. They were residents in suburban and urban areas of Bangkok, Thailand. These volunteers consisted of 174 smokers and 97 non-smokers. The study measured overall homocysteine concentrations, as well as plasma vitamin B12 levels.
The results indicated that smokers had higher levels of homocysteine and very low levels of vitamin B12, indicating a vitamin B12 deficiency. The scientists have hypothesized that the toxic substances inherent in cigarettes deactivate the vitamin B12.