**Vitamin D3** at 5,000 IU in one softgel sits at the very top of the clinically used 1,000–5,000 IU range — a full repletion-level dose for raising low blood levels and supporting bone and immune health. It's cholecalciferol, the form your body uses most efficiently, suspended in flaxseed oil so it absorbs well even without food.

This dose is built for a real gap — diagnosed deficiency, little sun exposure, or darker skin, where 5,000 IU a day actually moves your numbers. Because vitamin D pulls calcium into your body, many people pair a dose this high with vitamin K2 to steer that calcium toward bone rather than arteries.

One caveat: 5,000 IU is above the 4,000 IU daily upper limit, so this isn't a casual top-up. If your levels are already healthy, daily use can push you too high — the label rightly asks you to monitor your blood levels and check with a provider before long-term use.