Vitamin D3 is necessary for strong bones because it helps the body use calcium from food. Vitamin D3 becomes especially important in northern climates, where the limit of optimal vitamin D levels is below the norm for many people in cooler periods. However, in the case of a weak immune system, inflammations can occur more easily in a body exhausted from the stress and cold of the dark time. Prevent this with quick and easy-to-use vitamin D3 spray, which is also absorbed 3 times more effectively than vitamin tablets and capsules.