John M Pettifor

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Nutritional rickets remains a public health problem in many countries, despite dramatic declines in the prevalence of the condition in many developed countries since the discoveries of vitamin D and the role of ultraviolet light in prevention. The disease continues to be problematic among infants in many communities, especially among infants who are(More)
BACKGROUND Low- to middle-income countries are undergoing a health transition with non-communicable diseases contributing substantially to disease burden, despite persistence of undernutrition and infectious diseases. This study aimed to investigate the prevalence and patterns of stunting and overweight/obesity, and hence risk for metabolic disease, in a(More)
We examined undecalcified transiliac bone samples from 346 normal black and white South African adults (age range 21-83 years) by routine histomorphometry. The results were analysed for race-, age- and sex-dependent characteristics of trabecular microstructure (bone volume, trabecular thickness, trabecular number, trabecular separation) and static bone(More)
INTRODUCTION Nutritional rickets has been described from at least 59 countries in the last 20 years. Its spectrum of causes differs in different regions of the world. METHODS We conducted a systematic review of articles on nutritional rickets from various geographical regions published in the last 20 years. We extracted information about the prevalence(More)
In the United States, the higher prevalence of osteoporosis and the higher incidence of fractures in whites than in blacks may be attributed to the finding of lower bone density (BD) in both white children and adults. In South Africa, osteoporosis and fractures also occur more frequently in whites than in blacks. Appendicular BD has been found to be similar(More)
BACKGROUND Nutritional rickets remains prevalent in many tropical countries despite the fact that such countries have ample sunlight. Some postulate that a deficiency of dietary calcium, rather than vitamin D, is often responsible for rickets after infancy. METHODS We enrolled 123 Nigerian children (median age, 46 months) with rickets in a randomized,(More)
We investigated differences in physical activity (PA) levels between black and white South African 9-yr-old children and their association with bone mineral content (BMC) and density (BMD) by using dual-energy X-ray absorptiometry. PA was analyzed in terms of a metabolic (METPA; weighted metabolic score of intensity, frequency, and duration) and a(More)
A high incidence of long-bone fractures has been observed in children and young adults with quadriplegic cerebral palsy in residential care. This study aimed to determine factors that contribute to these fractures and to institute preventive treatment. Twenty individuals (12 males, eight females) of a cohort of 88 residents with spastic quadriplegia in(More)
Studies of nine children 4 7/12 to 13 years of age who had rickets are presented. No evidence of renal abnormalities, vitamin D deficiency, or of the inherited varieties of rickets was found. The salient features were their rural origins, mild hypocalcemia with evidence of secondary hyperparathyroidism, and improvement with a normal diet that contained an(More)