Project Summary

Effect of Vitamin D Supplementation on Fecal Shedding of E. coli O157:H7 in Naturally Colonized Cattle

Principle Investigator(s):
Tom S. Edrington, Russell L. Farrow, Kathryn M. Mckinnon, Todd R. Callaway, Robin C. Anderson, and David J. Nisbet
Food and Feed Safety Research Unit, Southern Plains Agricultural Research Center, USDA ARS
Completion Date:



Cattle derive vitamin D from both dietary sources and from the ultraviolet light conversion of 7-dehydrocholesterol in the skin. One of the three major target tissues of vitamin D is the intestine, where it stimulates transport of Ca and P across the intestinal brush border. Vitamin D, also known as the “sunshine vitamin”, is higher in the serum of cattle during the summer months. The seasonal increase in serum vitamin D concentrations taken together with its presence and active role in the intestine, led us to hypothesize that vitamin D may play a role in the seasonal prevalence of E. coli O157:H7. 

The objective of the current research was to examine the effect of supplemental vitamin D on fecal shedding of E. coli O157:H7 in naturally colonized cattle. 


Two experiments were conducted in which beef and Holstein steers were administered oral doses of vitamin D. In Experiment I, 14 crossbred beef steers (avg. BW = 225 kg) and 12 Holstein steers (avg. BW = 454 kg) were randomly assigned to control or vitamin D treatments. Fecal samples were collected daily for 6 d prior to, and during the 10-d period of vitamin D administration. Experiment II utilized 14 Holstein steers that were administered vitamin D daily in three successive doses: 2400, 4800, and 9600 IU/d each administered for 14 d. Fecal samples were collected daily and blood samples weekly throughout the 42-d study. 


In Experiment I, no differences in the percentage of Holsteins or beef calves shedding E. coli O157:H7 were observed prior to vitamin D treatment. However, during treatment administration, more calves in the vitamin D treatment tended (P = 0.11) to shed E. coli O157:H7 compared to controls (6.5 versus 14.3% for control and vitamin D treatments, respectively). Serum concentrations of vitamin D were markedly higher (P < 0.0001) in treated (782 nMol/L) versus control (258 nMol/L) calves. In Experiment II, no differences in fecal prevalence or serum vitamin D concentrations were observed for any of the vitamin D dosages. Differences in fecal shedding among the Holsteins and the beef calves in Experiment I are likely due to the difference in the vitamin D dose administered per unit of BW, as reflected in the serum concentrations of vitamin D. 


The long-term goal of this research is to determine if the complete removal of vitamin D from the ration in feedlot cattle in the summer could have a beneficial effect on E. coli O157:H7 populations or prevalence. As serum vitamin D concentrations are reported to be higher in the summer due to increased day-length and light intensity, we speculated that the removal of supplementary vitamin D would be offset by the seasonal increase and there would not be any adverse effects on performance or carcass quality. If our hypothesis that the summer elevation in vitamin D concentration is involved in the increased prevalence of E. coli O157:H7, then any change in E. coli prevalence should be associated with a change in serum vitamin D concentrations. This was observed in the first but not second experiment, supporting our hypothesis and further research in this area.