Quantification of vitamin D in commercial dog foods and comparison with Association of American Feed Control Officials recommendations and manufacturer-reported concentrations.

OBJECTIVE To quantify vitamin D (VitD) concentrations in commercial dog foods and compare those concentrations with Association of American Feed Control Officials (AAFCO) recommendations and manufacturer-reported concentrations. DESIGN Cross-sectional study. SAMPLE 82 commercial dog foods. PROCEDURES Samples of commercially available dog foods were obtained from owners of healthy dogs in the Guelph, ON, Canada, area and owners of dogs that were patients at the Ontario Veterinary College Health Sciences Centre's Mona Campbell Centre for Animal Cancer. For each food, the VitD concentration was determined by high-performance liquid chromatography-tandem mass spectrometry, and adherence to AAFCO and National Research Council recommendations was assessed. Analyzed VitD concentrations were compared with manufacturer-reported VitD concentrations and between wet and dry foods, among AAFCO nutritional adequacy statements (nutrient profiles vs feeding trials and adult maintenance vs all life stages), between foods sold only by veterinarians and those sold over the counter, and between small and large manufacturers. RESULTS The analyzed VitD concentration was below both AAFCO and National Research Council recommendations for one sample and below the assay detection limit for another. Analyzed VitD concentrations did not differ significantly from manufacturer-reported VitD concentrations or between wet and dry foods, among foods with different AAFCO nutritional adequacy statements, between foods sold only by veterinarians and those sold over the counter, or between foods produced by small and large manufacturers. CONCLUSIONS AND CLINICAL RELEVANCE Results suggested that manufacturer-reported VitD concentrations were accurate and that dog owners can be confident that VitD intake is adequate for AAFCO-compliant commercial dog foods.