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Investigations have been made on groups of South African preschool children, namely, rural and urban Negroes, Negro nursery school children, and whites, in respect to height, weight, and prevalence of PCM clinical stigmata. Because the Negro nursery school group who received two meals per day at school showed low prevalences of underweight, overweight, or clinical deficiency stigmata, they were used as a local standard of growth for comparative purposes. The relative values of local and international standards are discussed, and in their construction, stress is laid on the need for information on variables other than growth, including patterns of health experienced in later life.

In South Africa, enrichment of staple cereals is under consideration. In view of the known low calcium intake of three-quarters or more of the total population, a decision is required on what priority, if any, should be given to calcium supplementation.An examination has therefore been made of body processes and disease conditions likely to be prejudiced by a low calcium intake, namely, 1) growth, pregnancy and lactation; 2) bone composition and dimensions; 3) dental caries, rickets, osteomalacia and osteoporosis, and 4) nonskeletal processes. The conclusion is reached that there is no unequivocal evidence that an habitually low intake of calcium is deleterious to man, or that an increase in calcium intake would result in clinically detectable benefits.

It is widely accepted that the South African Bantu very seldom die from coronary heart disease, but that cerebral vascular disease constitutes an important cause of death. How valid are these beliefs? Since the diseases mentioned primarily affect the middle-aged and elderly, and since the Bantu are a relatively youngpopulation in contrast to agingwhite populations, specific mortalities from 45 to 64 years have been calculated for certain Bantu, and for a few white populations for comparison.Calculations suggest that mortality from coronary heart disease among Johannesburg urban Bantu in the 45–64-year age group, according to death-certificate data (assuming for the moment that such are valid), is, although still much lower than among most white populations, roughly of the same order as that in corresponding French, Italian, and Japanese population groups. Hence, for comparative purposes and when dealing with populations such as the Bantu, the importance of knowing age-specific as well as crude mortality rates for this disease will be obvious. Regarding the accuracy of these rates, whereas the mortality picture among the Johannesburg Bantu hospital population probably is reliable, that among the total urban population is far less certain. Still more uncertain is the position in rural areas, where deaths from this cause are believed to be very infrequent. Apart from the need for more exact knowledge of the mortality picture, it is evident that the large amount of information now available on Bantu unlikely to die from coronary heart disease must now be matched by the far more difficult task of securing antecedents as full as possible on those who do die, to learn whether affected persons were pursuing a traditional, partially, or fully westernized manner of life. Until all the combined information is available the full value of the Bantu for etiologic research will not be realized.Calculations also suggest that for Johannesburg Bantu in the 45–64-year age group, mortality from cerebral catastrophes actually is as high as that in most white populations, and that from cerebral hemorrhage probably is higher. While it is uncertain whether this mortality picture in the Bantu is accurate quantitatively, there is no doubt that cerebral vascular disease among them is a very important cause of death. The reason why these people are so prone to die from this cause is not clear. It is suggested that study of the relevant mortality in Bantu regional groups known to differ significantly in diet, salt intake, and blood pressure may throw some light on the subject.

Fibrinolytic activity in whole blood has been determined in groups of rural Bantu, urban Bantu and white subjects. It has been found that: (1) Mean activity in rural Bantu males is significantly greater than in urban Bantu males; both groups are significantly superior in activity to the white males studied. (2) Rural and urban Bantu females have significantly lower activities than the white females studied. (3) Fibrinolytic activity determined in groups of Bantu and white subjects at noon, followed by a fat-free or a fatty meal (31 to 34 gm. butter fat), shows no significant change when determined three hours later; in Bantu males and females there is a tendency toward acceleration of activity following ingestion of the fatty meal, whereas white females tend to show a slight inhibition of activity following both fat-free and fatty meals. (4) A group of rural Bantu pursuing active occupations did not have greater mean fibrinolytic activity compared with another group doing no active work during the experimental period, nor was a correlation apparent in the numerous individual Bantu and white subjects investigated.It is imperative to take account not only of the limitations of current methods of determining fibrinolysin activity, but also of our ignorance over the applicability of the results obtained to in vivoconditions. Nevertheless, the experimental in vitroobservations reported herein, indicating superiority in fibrinolytic activity of Bantu males over white males, but not of Bantu females over white females, demonstrate that higher fibrinolytic activity is not characteristic of the Bantu population. Caution must therefore be exercised against assigning undue importance to fibrinolytic activity (as assessed by the test used) in retarding the occurrence of acute thrombotic episodes in the coronary vessels of these people.