How is vitamin D poisoning diagnosed?
Most cases of vitamin D poisoning are diagnosed in pets that have the expected signs and a known or suspected exposure to Vitamin D-containing supplements, rat/mouse poisons, or psoriasis treatments. Blood work showing elevated levels of calcium, phosphorous, or markers of kidney damage increase the suspicion for vitamin D poisoning. A urine sample may be performed to help assess kidney function. In some cases, specialized testing to rule out other causes of elevated calcium may be necessary.
Dogs and Vitamin D
Dogs need a certain amount of Vitamin D in their diets to maintain a healthy balance of calcium and phosphorus in their bodies. This helps keep their bones healthy and plays an important role in the functions of muscles, nerves and all cells in the body.
There are two predominant types of Vitamin D. Ergocalciferol (D2) is derived from plants. Cholecalciferol (D3) is derived from animal sources. Dogs are not able to synthesize a significant amount of Vitamin D from the sun the way humans and some other animals can and therefore must get it from their diets. Dogs in the wild likely get most of their Vitamin D from eating animal fat. Some may come from eating plants.
Most commercial dog foods are supplemented with Vitamin D, but their levels can vary. Additional supplementation of Vitamin D is not usually needed. Ask your veterinarian for advice about Vitamin D and your dog. If needed, your vet can check your dogs levels and help you make any necessary adjustments.
What is vitamin D poisoning?
Vitamin D is necessary for the body to absorb calcium, a mineral that is essential for healthy bones, muscle movement, nervous system function, and immune system function. Excessive amounts of Vitamin D may result in poisoning. There are two forms of vitamin D. Plants, fungi, and yeasts produce Vitamin D2 (ergocalciferol) and Vitamin D3 (cholecalciferol) is produced by animals.
Poisoning commonly occurs when pets ingest rodenticides (rat and mouse poisons) containing cholecalciferol or supplements containing either form of Vitamin D. Vitamin D2 (ergocalciferol) has a much wider margin of safety than vitamin D3 (cholecalciferol) and larger amounts are generally more tolerated by animals. Many topical psoriasis medications also contain potent amounts of vitamin D (i.e., calcipotriene, tacalcitol, or calcitriol) and poisoning can occur when pets lick the cream off someone’s skin or directly from the tube of product. Improperly formulated pet foods, both commercially produced and homemade, have also resulted in poisoning.