Vitamin D is a nutritional component that is necessary in animal species for essential activities such as the development, growth, and metabolism of cells. Besides conventional functions, Vitamin D has a critical role in the normal functioning of the immune system. Deficiency of Vitamin D impairs innate and adaptive host responses.

Calcitriol (1,25(OH)2D3) is a pleiotropic molecule that has function in multiple biological processes which include regulation of bone mineral metabolism and modulation of immune responses.


Modern animal farming has put animals under great performance pressure that may result in compromised immune function leading to increased susceptibility to infection and inflammation.

The factors affecting immunity in animals are –

  • Age
  • Nutrient availability
  • Pathogens
  • Stress levels

The factors affecting Vitamin D availability –

  • Vitamin D loss during the metabolic processes
  • The complex pathway for Vitamin D absorption
  • Liver & Kidney health
  • Housing conditions


  • Recent studies indicate that vitamin D metabolites act on both, innate and adaptive immune systems. In response to invasion of pathogens, the immune system first executes innate and then adaptive defense mechanisms.
  • When Vitamin D intake is inadequate, the Vitamin D-dependent functions of the immune system may be impaired even though the animal does not exhibit symptoms of Vitamin D deficiency.
  • When Vitamin D is insufficient, the animal may be vulnerable to infectious diseases and may not reach peak production. Therefore, it is critical to ensure animals are getting sufficient Vitamin D.


(Nelson., 2014)

  • The antimicrobial defence of macrophages depend on the 1α-hydroxylase activity in macrophages and the availability of Vitamin D. If Vitamin D is insufficient, the immune system is weakened, and the animal is at a greater risk of infectious diseases.
  • 1α-hydroxylase is also produced by macrophages. These are unregulated during inflammatory reactions, and assist in increased production of 1,25(OH)2D3 (Vanherwegen et al., 2017).
  • 1α-hydroxylase activity in immune cells produces the 1,25 (OH)2 D3 that triggers innate defenses of the immune system by stimulating the production of defense proteins that kill bacteria.

Vitamin D has measurable effects on functioning of the immune system. Sufficient inclusion of Calcitriol (1,25(OH)2D3) in animal feed is not only essential for efficient growth and production but also for maintenance and enhancement of immune system function. Inclusion of Vitamin D enhances innate response mechanism against microorganisms. Vitamin D is efficacious for adaptive immune response vis-a-vis infection, vaccination, and regulation of inflammatory responses. (Shojadoost et al, 2021)

Furthermore, high concentrations of 1,25(OH)2D3 can be found in lymphoid micro-environments (Overbergh et al., 2000; Veldman et al., 2000; Chen et al., 2007), indicating an immunological role of the same. For proper functioning of the immune system, it is important to ensure that a sufficient level of 1,25 Dihydroxy D3 is available in the body.

Avitech Nutrition’s Avitriolis a product of natural origin derived from phytogenic sources containing calcitriol (1,25(OH)2D3)the metabolically active form of vitamin D3.  Avitriol delivers 1,25(OH)2D3 directly to the intestinal cells, bone cells, and eggshell glands without requiring any activation by the liver or kidney.

Avitriol is one of very few Vitamin D products in the feed industry available in its bioactive form. Avitriol is highly effective for cattle, poultry and swine and represents the most efficient method to ensure Vitamin D availability.