Mineral nutrition of Samburu adolescents: A comparative study of pastoralist communities in Kenya

Objectives: This study aimed to characterize mineral nutrition (copper, magnesium, selenium, and zinc) in Samburu pastoralist youth, in the context of differential cultural transitions due to uneven changes in educational access, herding intensity, polygyny, and access to wild, domesticated, and market-sourced foods. Materials and methods: Whole dried blood spots were collected in a total of 161 youth (highlands, n = 97; lowlands, n = 64) to assess concentrations of cadmium, copper, lead, magnesium, mercury, selenium, and zinc. Concentrations were determined through inductively coupled mass spectrometry. Dietary intakes were assessed by 24-h recall method and calculation of the probability of inadequate intakes. WHO protocols were applied to collect anthropometric measures in the youth. Results: Nearly half of the adolescents (47.8%) fell below the reference range for zinc status, and 88.2% had low zinc-to-copper ratios. High probability of nutrient inadequacies was evident for protein, fat, vitamins A, B₁₂, C, and E. In generalized linear modeling, lowland residence was negatively associated with zinc status and the zinc-to-copper ratio, and positively correlated with selenium and copper status. Other significant correlates were dairy livestock ownership; wife number of the youth's mother; meat consumption; vegetable consumption; protein intake; infectious disease morbidities; BMI; and hemoglobin concentrations. Discussion: In recent decades, Samburu pastoralists of northern Kenya have experienced marked dietary changes in the context of market integration, extreme drought, diminishing pasture availability, and violent civil conflict. Some children (particularly boys) successfully supplement their diets by foraging for wild foods, while others (particularly actively herding girls) may be more vulnerable.