Witamina D (25-OH)

Serum 25-hydroxyvitamin D measurement — the standard marker for vitamin D status. At 94 PLN (~€22), roughly a third of the price charged by German private labs for the same assay. Essential screening for anyone living at northern latitudes.

25-hydroxyvitamin D (calcidiol) is the accepted standard for assessing vitamin D status. It reflects combined dietary intake, supplementation, and cutaneous synthesis from UV-B exposure. The test measures total 25(OH)D, combining D2 (ergocalciferol, from plant sources) and D3 (cholecalciferol, from animal sources and sunlight). Deficiency is defined as below 20 ng/mL (50 nmol/L) and insufficiency as 20–30 ng/mL. Optimal levels for musculoskeletal and immune health are generally considered to be 30–50 ng/mL. At Szczecin's latitude (53°N), effective cutaneous vitamin D synthesis occurs only from approximately April through September — meaning supplementation is necessary for most of the year. Vitamin D receptors exist in virtually every tissue in the body. Beyond the well-established role in calcium absorption and bone health, adequate vitamin D status is associated with immune regulation, muscle function, cardiovascular health, and mood. The vitamin D-parathyroid hormone axis is clinically important: chronic deficiency triggers secondary hyperparathyroidism, which mobilises calcium from bone and contributes to osteoporosis. For a more complete bone metabolism assessment, Medicus offers parathyroid hormone (PTH) testing for 67 PLN and calcium panels from 23 PLN. The bone health package (Pakiet zdrowe kości) at 158 PLN combines vitamin D with calcium, phosphorus, and alkaline phosphatase.