Vitamin D status in female dogs with mammary gland tumors

Abstract

Background: Little information exists about vitamin D status in bitches with mammary tumors.

Objectives: To determine whether low plasma vitamin D concentrations are found in bitches with mammary tumors.

Animals: Eighty-five client-owned bitches with mammary tumors (n = 21 benign, n = 64 malignant) and 39 age-matched healthy bitches.

Methods: Case-control study. Plasma ionized and total calcium, phosphorus, magnesium, urea, creatinine, albumin, total proteins, alanine aminotransferase, alkaline phosphatase, parathyroid hormone (PTH), calcitriol (1,25-dihydroxyvitamin D), and 25-hydroxyvitamin D concentrations were measured in all bitches at the time of clinical diagnosis and before any treatments. Statistical analysis was performed to compare variables among groups (control, benign, and malignant).

Results: No significant differences were found when plasma 25-hydroxyvitamin D concentrations in bitches with malignant (148.9 [59.9] ng/mL) and benign mammary tumors (150.1 [122.3] ng/mL) were compared with control group (129.9 [54.5] ng/mL). Parathyroid hormone was significantly higher in bitches with malignant (19.9 [20.5] pg/mL), and benign mammary tumors (14.6 [14.9] pg/mL) compared with control group (7.5 [7.5] pg/mL; P < .01). Only the presence of mammary tumors (P < .01) and age (P = .04; adjusted R2 = .22) was significant in predicting PTH.

Conclusions: Bitches with mammary tumors do not have low 25-hydroxyvitamin D concentrations thus vitamin D supplementation is unlikely to be useful for prevention of mammary tumors in bitches.