New forms of vitamin D for animal and human health from plant origin
In modern animal meat production, undersupply of vitamin D results in skeletal problems because, and especially in poultry rearing, bone growth does not keep up with overall growth. However, Vitamin D itself does not possess biological activity but is transformed in 2 hydroxylation steps in the liver and kidney, respectively, into the active form 1,25-dihydroxy vitamin D3 (1,25(OH)2D3) which activates a gene inducing the synthesis of calbindin, the calcium binding protein responsible for the uptake of calcium from nutrition. Without the active metabolite 1,25(OH)2D3 no calcium can be absorbed, even if there is enough calcium contained in the diet.
Direct application of 1,25(OH)2D3 has been found to be the most active agent to prevent leg weaknesses and lameness in growing broiler chickens, in particular in modern breeds. A report of the scientific committee of the European Commission confirmed 1,25(OH)2D3 as the most effective agent in the prevention of tibial dyschondroplasia. Because synthetic 1,25(OH)2D3 is expensive and not available for animal nutrition, an alternative has been found in the plant Solanum glaucophyllum which contains the active form of Vitamin D3 in glycosidically bound form.
In order to exploit this plant as a source of active vitamin D, a unique standardized and formulated herbal product for animal nutrition containing 1,25(OH)2D3-glycosides as active components was developed. This affords better pharmacokinetic properties and turns the product into a slow release form with little danger of overdosing.
 EUROPEAN COMMISSION, the Welfare of Chickens Kept for Meat Production (Broilers), Report of the Scientifc Committee on Animal Health and Animal Welfare, page 33, adopted 21 March 2000, SANCO.B.3/AH/R15/2000