The most effective way to prevent micronutrient deficiencies in general and scurvy in particular is to consume a diet containing a variety of foods, including fresh foods. Emergency food supplies, however, usually consist of a staple (cereals), an energy source (oil), and a protein source (pulses), all of which contain virtually no vitamin C. Populations depending entirely on such a limited range of foods for more than two months run the risk of developing scurvy. According to WFP (1991), "where people are more or less totally dependent on food aid rations for long periods, without opportunities to produce or obtain other foods by trading or other means... a range of foods should be assured, including some fresh foods wherever possible (even if only on an occasional or irregular basis) in order to supply a diet which meets all essential nutrient requirements".
It is generally agreed that there are problems associated with meeting these principles in practice and that no single strategy that will ensure that adequate quantities of all essential micronutrients are provided to all demographic groups of refugees in every camp. Toole (1992) stresses that at every stage of an emergency programme, refugees should be provided with opportunities to diversify their dietary intake through free exchange of rations in local markets, cultivation of vegetables in camp gardens, and employment programmes.