Vitamin A Food Sources
Preformed vitamin A from animal tissue is the most bioavailable form of the vitamin, with good sources being liver (chicken or cow), eggs, meat, milk, cheese, and – for infants – breast milk.
Food consumption interviews with clinic patients revealed that the diets of most people in and
near La Guamita are low in animal products. While chicken and/or eggs might be eaten once a week, the primary protein source for the community is the ubiquitous rice and beans. Apart from low intake, low tissue vitamin A availability can result from inadequate intakes of protein, calories and zinc, needed to make retinol-binding protein, which is essential for mobilizing vitamin A from the liver and transporting it. Even though food diversity was limited in La Guamita, food scarcity did not appear to be a problem. The protein provided by a diet of rice and beans appeared to be adequate, and zinc tends to follow protein in foods, with grains and legumes being a good source.
Breast-feeding is recommended to provide adequate vitamin A to infants. One mother with an infant indicated her intention to breast-feed her child for 1–2 years. Observation of other mothers and infants revealed a mix of breastfeeding and bottle-feeding of infants under the age of two years.
Several hundred carotenoids occur in food, but only approximately 50 can be converted into retinol (vitamin A). Among these, β-carotene has the greatest pro-vitamin A activity. The rate of conversion is at present under discussion.
Plant foods high in β-carotene include dark green leafy vegetables (broccoli, spinach, romaine lettuce) and yellow/orange vegetables and fruits (carrots, sweet potatoes, pumpkins, apricots, cantaloupe and mangos). Of the
fruits and vegetables grown and available in La Guamita – mangoes, pineapple, bananas, oranges, avocado – only mango is high in provitamin A. Unfortunately, the growing season for mangos is only July and August. Lettuce, tomatoes, and carrots are available year-round, but are more often obtained in stores rather than local gardens. 
Of these, carrots have the greatest pro-vitamin A content but are reported to be eaten rarely in La Guamita. Likewise, pro-vitamin A rich pumpkins, sweet potatoes, and yams could be grown in the climate of La Guamita, but are not. Therefore, in terms of vitamin A food sources, it appears that the most prevalently available and consumed source is the mango, but only in the months of July and August. Unless carrots are included in the diet, vitamin A food sources consumed the remaining ten months of the year appear to be minimal, and are of animal origin.