Dvitamiinin

Dvitamiinin is a fictional nutrient described in speculative biology and science fiction as a lipophilic, vitamin-like molecule that regulates calcium and bone metabolism in a manner reminiscent of real vitamin D.

In fictional accounts, it is a secosteroid-like compound with a flexible side chain. It is said to be fat-soluble and to accumulate in adipose tissue, with dietary sources ranging from certain plants or microbes and, in some narratives, synthetic analogs.

Biologically, Dvitamiinin is depicted as binding a nuclear receptor analogous to the vitamin D receptor, influencing gene expression related to intestinal calcium absorption, bone remodeling, and immune function. Its signaling is often described as synergistic with parathyroid hormone in fiction.

Activation and metabolism are described as a two-step process beginning with a skin- or tissue-produced precursor, followed by hydroxylation to a bioactive form. Catabolic routes and storage resemble those of real secosteroids, though specifics vary by author.

Because Dvitamiinin is fictional, no clinical guidelines exist. In-universe, excessive intake could cause hypercalcemia and soft tissue calcification, while deficiency leads to impaired mineralization. The concept is used mainly as a narrative tool to explore vitamin-like biology.