Studies on the Serum Total Carotenoids, Vitamin a and Serum Colour in Nigerian Soldiers.

In Western Nigeria samples of serum or plasma are often bright yellow and yet have normal levels of bilirubin. In a pilot experiment in 1959 we found that unusually high levels of total carotenoids were present in several samples of yellow serums. Edozien (1960) has since reported values for serum carotene in Ibadan ranging from 150 to 900 pg/Ioo ml in normal individuals, compared with the figure of 200 pglioo ml accepted as the upper limit of normal in persons living in the United Kingdom (Moore, 1957; Varley, 1958). Edozien suggested an association with the dietary intake of palm oil and peppers. More recently Dagadu & Gillman (1963) have reported values above 500 pglroo ml in 80% of individuals in a study in Accra, Ghana. I n the investigation here reported the observations of the pilot experiment were expanded by a study of the relation between the total carotenoid levels of the serums and their yellowness as measured by the icteric index. The values for serum total carotenoids in healthy Nigerian soldiers obtained during this study form a useful addition to Edozien’s (1960) figures, as they refer to a different city (Lagos) and have been obtained for a group of soldiers living on a diet rather better than the regional average. At the same time the vitamin A levels were studied, and in a few individuals it was also possible to measure a-tocopherol levels, for which no data are as yet available from this city. A survey of the diet was made to discover what sources of carotenoids were present and to assess its adequacy. The carotene content of a local sample of palm oil was also measured. Our findings confirmed that the total carotenoid levels in serum were above European levels, often by a considerable amount, and correlated well with the yellowness of the serums, provided that the bilirubin was not abnormally elevated. Vitamin A levels were found to be towards the upper limits of the accepted range of normal values, and a-tocopherol was within or slightly below the normal range.