Micronutrient malnutrition, the lack of vitamin A in particular, is one of the major public health problems in less developed countries. It can lead to blindness and death in children under five years of age. Globally, an estimated 250 million preschool children are vitamin A deficient, of which about 250,000 children become blind every year. As a consequence, half of them die within 12 months of losing their sight. About 25% of mortality rates among young children can be reduced by correcting vitamin A deficiency at the community level (Beaton et al., 1993).
There is increasing demand from researchers, donors, and governments to assess the risk vitamin A deficiency at individual, household, and community level; which is mainly driven by the importance of understanding the existing vitamin A deficiency (VAD) level an as well as plan implementation programs to reduce it. The conventional methods used to assess vitamin A deficiency include xerophthalmia (eye damage) prevalence, dietary assessment, and biochemical analyses of serum retinol or retinol binding protein. However, these techniques require specialized skills and resources. Vitamin A intakes are best assessed through consumption studies where either all foods consumed are weighed before eating, or using recall methods of foods consumed, usually during the past 24 hours. Clearly, assessing both VAD status and vitamin A intakes is expensive and often beyond the scope of nutrition interventions that are trying to go-to-scale. Helen Keller International invested in developing a semi-quantitative, food frequency method that looked at the frequency of intake of vitamin A rich foods and validated these results against serum retinol values (Rosen et al., 1993). This method is used to assess whether a given population is at risk of VAD. It can also help monitor which vitamin A foods, such as OFSP, are coming into the diet by season and over time.
Subsequently, the 24-VASQ method was developed for estimating vitamin A intake of populations in a simpler way than 24 hour recall of all foods consumed (dee Pee et al., 2006). It can be used in large surveys and surveillance systems to quantify vitamin A intake of specific population groups, monitor changes in intake through time, compare intake among populations, identify the contribution of four different food groups – vegetables, fruits, animal foods and fortified foods – to vitamin A intake and identify populations at risk of vitamin A deficiency. However, it is also too time consuming to serve as a quick, low cost monitoring tool.