Minstry of Agriculture - Food Security Technical Secretariat

نظام معلومات الأمن الغذائى فى السودان

الأمانة الفنية للأمن الغذائي في السودان
الرئيسية >> نظام رصد الأمن الغذائي

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مؤشرات جودة الاغذية والمغذيات الدقيقة - انتشار نقص فيتامين (ألف) في عدد السكان

Prevalence of vitamin A deficiency.
Statistical Concepts And Definitions: The prevalence of vitamin A deficiency is the proportion of total population with serum retinol equal or lower than 0.70 μmol/l.
Relevance: "Retinol is the predominant circulating form of vitamin A in the blood. In response to tissue demand, it is released from the liver in a 1:1 ratio with its carrier protein, retinol-binding protein. In the blood, this complex combines with transthyretin. Specific receptors on target cell surfaces or nuclei bind this complex or its active metabolites, thereby regulating many critical functions in the body, including vision, epithelial tissue integrity, and the expression of several hundred genes. Serum retinol levels reflect liver vitamin A stores only when they are severely depleted (< 0.07 μmol/g liver) or extremely high (> 1.05 μmol/g liver). Between these extremes, serum retinol is homeostatically controlled and thus not always correlated with vitamin A intake or clinical signs of deficiency. Consequently, serum retinol is not useful for assessing the vitamin A status of individuals and may not respond to interventions. Rather, the distribution of serum retinol values in a population and the prevalence of individuals with serum retinol values below a given cut-off can provide important information on the vitamin A status of a population and may reflect the severity of vitamin A deficiency as a public health problem, especially when the degree of underlying infection or inflammation is taken into account. Serum retinol values are most often measured in young children, a group highly vulnerable to deficiency. Deficiency of vitamin A is associated with significant morbidity and mortality from common childhood infections and is the world’s leading preventable cause of childhood blindness. The cut-off values for public health significance is 20%. A prevalence of Vitamine A deficiency equal or higher than this level signals a severe public health problem."
Unit Of Measure: Percent
Time Coverage: 1990-2016

No data available

Source Data: World Health Organization (WHO): http://www.who.int/vmnis/database/vitamina/countries/en/index.html.