Determinants of vitamin D status in Kenyan calves

Abstract

Vitamin D plays a critical role in calcium homeostasis and in the maintenance and development of skeletal health. Vitamin D status has increasingly been linked to non-skeletal health outcomes such as all-cause mortality, infectious diseases and reproductive outcomes in both humans and veterinary species. We have previously demonstrated a relationship between vitamin D status, assessed by the measurement of serum concentrations of the major vitamin D metabolite 25 hydroxyvitamin D (25(OH)D), and a wide range of non-skeletal health outcomes in companion and wild animals. The aims of this study were to define the host and environmental factors associated with vitamin D status in a cohort of 527 calves from Western Kenya which were part of the Infectious Disease of East African Livestock (IDEAL) cohort. A secondary aim was to explore the relationship between serum 25(OH)D concentrations measured in 7-day old calves and subsequent health outcomes over the following 12 months. A genome wide association study demonstrated that both dietary and endogenously produced vitamin D metabolites were under polygenic control in African calves. In addition, we found that neonatal vitamin D status was not predictive of the subsequent development of an infectious disease event or mortality over the 12 month follow up period.

Low serum vitamin D concentrations in Spring-born dairy calves are associated with elevated peripheral leukocytes

“…Therefore, our results suggest that although IL-8 genotype shapes Vit D responses, other molecular factors are associated with the Vit D status in cattle. In fact, a recent genome-wide association study in African calves had found serum 25OHD concentration to be under polygenic control 33 . Therefore, environmental and host factors can contribute to changes in the Vit D status of cattle.…”

Vitamin D status is heritable and under environment‐dependent selection in the wild

“…We also predicted heavier sheep would have higher vD 2 concentrations, since this suggests these sheep are better foragers. Further, associations with total vD and vD 3 concentrations and coat colour have previously been documented in other ruminants (Callaby et al, 2020;Zhou et al, 2019) and so we expected sheep with dark coats to have lower concentrations of these vitamin D metabolites. Although solar radiation is a considerable driver of vitamin D status in human populations (Holick, 2007), we only had data for 6 years in this population; individual exposure levels were highly similar between all sheep measured within a given year due to the small range of sampling dates in August.…”

“…We found that Soay sheep females had higher vitamin D concentrations, but only after accounting for weight. A study in cattle found no association between sex and total vD concentrations (Callaby et al, 2020), suggesting that the sex differences in humans may be due to differences in behaviour and diet which do not occur in domestic ruminants. Third, we found that dark coated sheep had considerably lower total vD and vD 3 , which is consistent with studies in other sheep breeds (Zhou et al, 2019) and cattle (Callaby et al, 2020).…”

“…A study in cattle found no association between sex and total vD concentrations (Callaby et al, 2020), suggesting that the sex differences in humans may be due to differences in behaviour and diet which do not occur in domestic ruminants. Third, we found that dark coated sheep had considerably lower total vD and vD 3 , which is consistent with studies in other sheep breeds (Zhou et al, 2019) and cattle (Callaby et al, 2020). This implies that darker coats are absorbing more UVB radiation which reduces the cutaneous production of vitamin D. Fourth, while a negative association between vitamin D status and BMI has been reported in human populations (Pereira‐Santos et al, 2015; Zakharova et al, 2019), we found a positive association with weight in the Soay sheep.…”

La vitamina D en la salud y en las patologías del bovino: un enfoque no clásico

“…En contraste, Hymøller y Jensen (2010) postulan que la piel es la fuente principal de esta vitamina en el ganado en pastoreo. En relación a la síntesis cutánea, se ha reportado que los terneros con pelaje de colores más oscuros presentan concentraciones séricas de 25(OH)D total y 25(OH)D 3 más bajas que los terneros con pelaje mixtos (Callaby et al, 2020).…”