Solgar Vitamin D3 4000 IU is a premium, high strength formula that includes vitamin D3, a form that is easy for the body to use. The benefits of the sunshine vitamin are numerous and well documented, ranging from supporting immunity, to strong bones and healthy teeth. In addition to changing your diet and lifestyle, taking a Vitamin D supplement is a good way to top up your levels especially in winter months. Particularly important when you take into account, over a billion people worldwide have very low levels of Vitamin D.Solgars Vitamin D3 is the highly absorbable form of Vitamin D, Cholecalciferol, which offers maximum absorption delivering 4000 IU per capsule.