Epidemiology of Vitamin B12 Deficiency

Abstract

Although vitamin B12 deficiency is considered to be a public health problem, its incidence and prevalence are not exactly known. The reasons for this condition are the ethnic and sociocultural differences between societies and their varying dietary habits. The most comprehensive knowledge about vitamin B12 deficiency has been extracted from a review, which was conducted through studies in Africa, America, South‐East Asia, Europe, Eastern Mediterranean, and Western Pacific in 2008 [10]. Another review evaluated 41 studies in Latin America and the Caribbean and found that the prevalence of vitamin B12 deficiency was 61% [11]. The data extracted from this study have shown that vitamin B12 deficiency is still a public health problem in these regions. The main reasons for vitamin B12 deficiency are nutritional deficiencies that affect large sectors of the population including vegetarians and their children who are affected during and after pregnancy, the elderly, frequent drug users as well as nutritional deficiency linked to low socioeconomic level [5]. Vitamin B12 deficiency among vegetarians was found to be between 21 and 85% regardless of age, address, type of vegetarianism, and demographics of the individuals concerned (Table 1) [12]. Although it is thought that vitamin B12 deficiency is rarely seen except in strict vegetarians, it is, in fact, commonly seen in all vegetarian groups (lacto‐vegetarians, ovo‐vegetarians, lacto‐ovo‐vegetarians, and vegans), as well as among the elderly and for reasons related to medicine and drug use [12‒15]. Particularly, vegetarians should take care of protective measures for vitamin B12 deficiency that involve to identify the inadequate vitamin level and to receive supplements containing B12 in necessary condition [12]