Lack of sunlight – for bones, muscles and the immune system Sunlight activates the production of vitamin D3 in the skin, which plays an important role in bones, muscles, and the immune system. Therefore, this product is suitable, for example, for taking during the darker months to prevent a vitamin D3 deficiency. Vitamin D3 is involved in countless metabolic processes and contributes to the normal function of the immune system, muscles, and the maintenance of normal bones in the body. Vitamin K2 supports the maintenance of normal bones. Plant-based Omega 3 from linseed oil contributes to a balanced supply of alpha-linolenic acid. No artificial flavors. No artificial colors. No preservatives.