1. Upon receipt of the Total 25-OH Vitamin D ELISA kit, store it at 2-8°C and avoid light exposure (do not freeze the kit or hold it at temperatures above 25°C).
2. The kit should not be used after the expiration date.
Vitamin D is a group of secosteroids of which vitamin D2 (ergocalciferol) and vitamin D3 (cholecalciferol) are the most important to humans. In animals, vitamin D3 is generated in the skin by the reaction of sunlight with a precursor molecule. In plants, vitamin D2 is formed via a related photochemical process from ergosterol. In either case, vitamin D3 and D2 are biologically inactive and metabolized into 25-hydroxyvitamin D3 (25-OH vitamin D3) and 25-hydroxyvitamin D2 (25-OH vitamin D2), the main forms of vitamin D in the body. Due to its abundance and long circulating half-life, 25-OH vitamin D levels are the best indicator of vitamin D status. 25-OH vitamin D can also be converted to 1,25-(OH)2 vitamin D, but it has a short half-life in the body and does not typically correlate as directly to vitamin D levels. Vitamin D deficiency is an important risk factor for bone health (rickets, osteomalacia and senile osteoporosis), cancer, and pregnancy outcomes. Vitamin D toxicity can cause general symptoms such as weight loss, heart arrhythmias, and anorexia as well as more severe complications including kidney, heart, and blood vessel damage.