Vitamin D 5,000 IU by Ortho Molecular Products

This dose fits adults whose Vitamin D, 25-Hydroxy is low or low‑normal and who want a meaningful bump within 8 to 12 weeks. It’s useful if you get little sun, have darker skin, use sunscreen consistently, live at northern latitudes, or have higher body weight. It also helps after bariatric surgery or with malabsorption conditions like celiac or inflammatory bowel disease. If your level is already mid-to-high, 5,000 IU is often more than a maintenance dose.

Cholecalciferol (vitamin D3) is the form your skin makes from sunlight, and it raises blood levels more reliably than D2 (ergocalciferol). Your liver and kidneys convert D3 into the active hormone that increases calcium absorption from the gut and keeps parathyroid hormone (the signal that pulls calcium from bone) in check. Adequate vitamin D also influences immune signaling and muscle function, but effects on colds and mood are modest unless you start out low.

Take once daily with a meal that contains fat to improve absorption. Expect your Vitamin D, 25-Hydroxy to reflect the new steady state in 8 to 12 weeks; that’s the right time to re-test and adjust. For many, 5,000 IU is a repletion-level dose. Once your level is where you want it, a lower daily maintenance dose (often 1,000–2,000 IU) is typical. Magnesium status matters, since it’s used to activate vitamin D.

Avoid high-dose vitamin D if you’ve had high calcium, recurrent calcium kidney stones, primary hyperparathyroidism, sarcoidosis, or lymphoma, unless managed by a clinician. Thiazide diuretics (blood pressure meds that raise calcium) increase the risk of high calcium with vitamin D. Orlistat and cholestyramine reduce absorption; take vitamin D several hours apart. Anticonvulsants and rifampin increase breakdown, so dosing often needs clinician guidance.