The first step when analyzing data for Vitamin A deficiency after cleaning and characterizing the data, is to decide if there is a reason for concern that the deficiency exists (this is at least true for vitamin A and iodine deficiency). The question to ask is if the deficiency exists in a certain region or population. The first place to explore this question in the data is in the groups that are known to be vulnerable through previous studies. These groups for Vitamin A deficiency are children in years of rapid growth (but especially children 0-5 years), pregnant women, and refugees. Young children are the most vulnerable for several reasons- they are growing quickly (increasing their bodies needs for all nutrients), they have more frequent illness, they consume less food during illness (in general) such as vitamin A foods and fats, which help absorption of vitamin A. Babies who are born low birth weight start with a disadvantage since they have a smaller store of vitamin A in the liver than children of normal birthweight. Those children who are not breastfed exclusively for the first 4-6 months and not fed the first milk (colostrum) are also deprived of some of the natural vitamin A rich breastmilk. Pregnant women experience higher nutrient demand in general during pregnancy, which includes increased demands for vitamin A for the fetus to develop normally (caution must be practiced to avoid the teratogenic effects of excessive vitamin A during pregnancy).

Now, using the data collected in Cambodia (cambodia.sav), try compiling a description of vitamin A deficiency indicators in the dataset to give a picture of the "vitamin A deficiency situation" for different sub-populations, especially focusing on those just mentioned that are at higher risk for vitamin A deficiency. It might also be useful to give the prevalence of some other influencing factors along side the prevalence of vitamin A deficiency indicator. These might include, disease prevalence (diarrhea, fever, and helminth infection), immunizations (especially measles), income level of the home, access to safe water/ sanitation, access to health care, etc. The goal is to begin to display a summary of what the population looks like in terms of VAD risk.