Avitaminosis

Avitaminosis refers to a deficiency of one or more vitamins that impairs normal bodily functions. It can arise from inadequate dietary intake (primary deficiency) or from problems with absorption, metabolism, or increased requirements (secondary deficiency). The specific symptoms and severity depend on which vitamin is deficient and how long the deficiency has persisted.

Commonly affected vitamins and features include vitamin A deficiency with night blindness and keratopathy; vitamin C deficiency causing scurvy; vitamin D deficiency leading to rickets in children and osteomalacia in adults; thiamin (vitamin B1) deficiency causing beriberi and Wernicke-Korsakoff syndrome; vitamin B12 deficiency resulting in anemia and neuropathy; and vitamin K deficiency associated with bleeding tendencies. Fat-soluble vitamins (A, D, E, K) tend to accumulate and can cause toxicity with excessive supplementation, while water-soluble vitamins (B-complex and C) are more readily excreted but can still cause deficiency with poor intake or malabsorption.

Diagnosis is based on clinical signs, dietary history, and laboratory tests of vitamin levels or related functional markers; in some cases the diagnosis is supported by a positive response to supplementation. Treatment involves targeted vitamin repletion and management of any underlying cause, with careful monitoring for potential adverse effects, particularly for fat-soluble vitamins.

Prevention emphasizes a balanced diet that includes a variety of fruits, vegetables, grains, and fortified foods, along with appropriate supplements for at-risk groups such as infants, pregnant individuals, older adults, or people with malabsorption or restricted diets, under medical supervision.