Nutrition of Nigerian Peasant Farmers, with Special Reference to the Effects of Vitamin A and Riboflavin Deficiency

Abstract

During 1947-48 a clinical and dietary survey was carried out in Niger Province upon three groups of racially similar peasant farmers, living under similar climatic conditions, and eating mainly the same staple foodstuffs. The dietary survey was quantitative. The food of the adult members of three families in each area, in all 46 persons, was weighed and measured for 4 periods of 7 days each, the periods being distributed throughout the year. The staple foodstuffs in all areas were Guinea-corn and bulrush millet, cassava and sweet potatoes were used to a less extent, cow-peas and green leaves were used in small quantities. The intake of animal protein was very low, most of it being obtained from dried river fish. The outstanding dietary difference between the areas was that in one area (Bida) red palm oil was plentiful, but was almost unobtainable in the other two areas (Kontagora and Zuru), where it was partially replaced by shea-nut oil and a little butter. Evaluation of the diets by the use of tables showed that in all three areas calcium and riboflavin were deficient, the intake of the latter being a third more in Zuru than in Bida and Kontagora. The intake of fat and vitamin A was high in Bida and low in the other two villages. Clinical examination of sample groups of individuals was carried out in the three areas. No considerable variation in general status was found. However, the incidence of a number of stigmata associated with nutritional deficiency, varied considerably in the different villages, and comparison of this incidence with the respective dietary intakes has led to the following conclusions: - " (1) Vitamin A deficiency results in dry and staring hair and hypochromotrichia, generalized xerosis and follicular hyperkeratosis, ' elephant skin, ' ' crackled ' skin and night-blindness. " (2) Deficiency of riboflavin results in angular stomatitis, permanent gooseflesh; nasolabial seborrhoea, and increased vascularity of the conjunctiva. " (3) Folliculosis of the skin and proliferative lesions of the bulbar conjunctiva are not due to deficiency of vitamin A, but are more likely to follow a prolonged low intake of riboflavin, if, indeed, they are in any way attributable to malnutrition." Clinically demonstrable liver disease (7 to 15 per cent.) with urobilinogenuria (36 to 47 per cent.) was relatively common and was considered to be an important contributary factor in determining the occurrence of deficiency disease. Mean haemoglobin levels in the three areas ranged from 70 to 76 per cent. (Sahli. 100 per cent. = 14 gm. per 100 ml.). [This interesting survey adds to our knowledge of the relative importance of deficiency of vitamin A and riboflavin in the production of lesions of the eyes, the hair, and the skin. There are some points, however, which suggest that the clinical differences between the regions may not have been, in fact, so great as they appear in the tables. There was an age bias in one of the samples which considerably alters the magnitude of the differences observed, particularly in relation to dry, staring hair and hypochromotrichia. These signs, the author states, were more frequent in children than in adults. In Bida, where vitamin A intake was high and the incidence of these manifestations was low, there were in the sample only 8 children out of a total of 92 persons examined; whereas in Kontagora there were 17 children in a total of 93, and in Zuru 13 in a total of 79.] Dean A. Smith.