Spatial distribution of calcium in food, water and soil and its possible influence on rickets disease in Northern Nigeria

Nutritional rickets around the world: an update

Worldwide, nutritional rickets continues to be an evolving problem with several causes. This paper provides an updated literature review characterising the prevalence, aetiology, pathophysiology and treatment of nutritional rickets worldwide. A systematic review of articles on nutritional rickets from various geographical regions was undertaken. For each region, key information was extracted, including prevalence, cause of rickets specific to the region, methods of confirming the diagnosis and current treatment and preventive measures. Calcium deficiency continues to be a major cause of rickets in Africa and Asia. Vitamin D deficiency rickets is perhaps increasing in the Americas, Europe and parts of the Middle East. There continues to be a distinct presentation of calcium-predominant versus vitamin D predominant rickets, although there are overlapping features. More careful diagnosis of rickets and reporting of 25-OHD concentrations has improved accurate knowledge of rickets prevalence and better delineated the cause. Nutritional rickets continues to be an evolving and multi-factorial problem worldwide. It is on a spectrum, ranging from isolated vitamin D deficiency to isolated calcium deficiency. Specific areas which require emphasis include a consistent community approach to screening and diagnosis, vitamin D supplementation of infants and at-risk children, prevention of maternal vitamin D deficiency and the provision of calcium in areas with low calcium diets.

Evaluating environmental and social influences on iron and zinc status of pregnant subsistence farmers in two geographically contrasting regions of Southern Malawi

Micronutrient deficiency affects over 4.5 billion people worldwide, the majority in developing countries. Deficiencies of iron (and associated anaemia) and zinc in pregnancy are associated with complications, maternal and neonatal mortality, and developmental disorders in the foetus and growing child. We report the results of pilot study which used an interdisciplinary approach to explore environmental and sociocultural factors influencing the micronutrient status in the soil-plant-human transfer for pregnant subsistence farmers in two geographically contrasting regions of Southern Malawi. It evaluated micronutrient status in soil and the staple crop and explored the context for their transfer to pregnant women. Scientific and social science methods were used to collect data, following full sensitisation of the communities. A total of 99 participants were recruited from Chiradzulu (plateau) and Chikwawa (floodplain). Soil, maize and blood samples were collected, along with food frequency and health behaviour questionnaires and anthropological observation. Statistical analysis revealed that soil iron was significantly higher in Chiradzulu than in Chikwawa; total iron concentration is not deemed to be deficient in either area. Soil zinc was not significantly different between areas. Maize concentrations of iron and zinc were not significantly different between areas, and were not deficient relative to improved cultivars. Blood iron deficiency and associated anaemia were problematic in both areas, but more so in Chikwawa than in Chiradzulu, and zinc deficiency was similar in both areas. The study has identified a significant difference in the blood iron status of the participants of the two communities, and has shown that this difference is not accounted for by the staple crop maize. Socio-geographical factors appear to play a significant role in the micronutrient health of the populations. The findings lend support to multifaceted community intervention studies which educate communities on strategies to tackle micronutrient deficiencies.