Academic journal article Journal of Health Population and Nutrition

Vitamin [B.Sub.12] Levels of Subjects Aged 0-24 Year(s) in Konya, Turkey

Academic journal article Journal of Health Population and Nutrition

Vitamin [B.Sub.12] Levels of Subjects Aged 0-24 Year(s) in Konya, Turkey

Article excerpt


Vitamin [B.sub.12] is a water-soluble vitamin that is an essential co-factor in some biochemical reactions and required for the synthesis of both RNA and DNA. Its deficiency may cause disorders, especially in the haematologic, neurologic, and gastrointestinal systems. Deficiency in infancy may lead to mental retardation and may have lifelong effects (1).

Reports indicate that vitamin [B.sub.12] levels show racial differences; thus, using the reference ranges of varied populations may lead to inaccurate results (2-6). Therefore, normal levels that are valid for each population should be obtained. To the authors' knowledge, no research in the literature addressed reference ranges of vitamin [B.sub.12] for the population of Konya region of Turkey. The authors designed this work to determine the normal levels of vitamin [B.sub.12] in this region.


The study was conducted during May 2006 to March 2007. It screened samples of 1,109 subjects aged 0-24 year(s) (560 boys, 549 girls), including 54 cord-blood samples. The cord-blood was obtained through the umbilical cord at the time of birth in the Department of Obstetrics and Gynaecology, Selcuk University Hospital in Turkey. The other subjects were patients admitted to primary healthcare centres for any complaint. The study followed the guidelines set forth in the Declaration of Helsinki, and the procedures were approved by the Ethics Committee of Selcuk University Meram Medical Faculty.

Blood samples were obtained from persons undergoing blood analyses for other reasons. Twenty-eight of the cord-blood samples were collected from male babies and 26 from females. The distribution of subjects by age was as follows: newborn group (45 subjects; 23 boys, 22 girls), 1-12 month(s) (38 subjects; 17 boys, 21 girls), and 13-24 months (52 subjects; 32 boys, 20 girls). In each age-group from 24 months to 24 years, there were 20 boys and 20 girls for every year. Samples were obtained after administering a questionnaire consisting of 16 items about conditions that can affect the status of vitamin [B.sub.12] to determine suitability of subjects for the study.

The first section of the questionnaire recorded age, sex, height, weight, body mass index [BMI: weight (kg)/height [(m).sup.2]] as well as occupation, educational status, and monthly income of parents. The second section queried the medical history (disease, operations, drugs), and the third section established the nutritional status of the study group, with questions regarding fish, chicken, or red meat consumption in the previous three days and the frequency of seafood, red meat and offal consumption. Since the most important source of vitamin [B.sub.12] is red meat, consumption of red meat at least twice per week was the standard for inclusion into the study, and the subjects consuming less than that were excluded. The third section of the questionnaire asked also about the foods normally consumed at breakfast. In children who were breastfed, the study considered the nutritional status of the mother. When essential, the results of a physical examination informed the decision of including a patient. As the study was designed to determine the normal levels of vitamin [B.sub.12], those considered to have nutritional deficiency were not included. Other exclusion criteria were: (i) history of renal, haematologic, gastrointestinal or metabolic disease (leukaemia, polycythaemia, hypereosinophilia, cystic fibrosis, hepatitis, cirrhosis, cancer), gastrointestinal surgery, malnutrition, growth retardation, malabsorption, or prematurity; (ii) taking drugs containing vitamin [B.sub.12]; (iii) pregnant women taking [B.sub.12]-containing vitamins (for cord-blood); (iv) infants being formula-fed; (v) use of any anti-epileptic drug; (vi) drinking alcoholic beverages and/or smoking; (vii) history of parasitic infections; and (viii) emigrants of other races.

Researchers obtained informed consent from all participants or their parents (for children below 18 years of age). …

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