NOW Vitamin D3 400IU Drops is a liquid supplement that provides vitamin D3 in an easy-to-take dropper form. The 59ml bottle contains vitamin D3 (cholecalciferol) which helps support bone health, immune function, and calcium absorption in the body. The liquid dropper format allows for flexible dosing and may be particularly suitable for those who have difficulty swallowing pills or capsules. Vitamin D3 is a fat-soluble vitamin that plays an essential role in maintaining healthy bones and teeth by promoting calcium absorption. It also supports proper immune system function and overall health. The amber glass bottle helps protect the vitamin D3 from light degradation to maintain potency.