Can you tell me how kidney activate vitamin d?

An enzyme.: The Vitamin D that we get from our diet and what is made in our skin with the help of sunlight is initially inactive and must become activated in order to exert its effects in our bodies. Healthy kidneys contain an enzyme called 1-alpha-hydroxylase that converts inactive Vitamin D into active Vitamin D.

Yes: Steps of metabolism for d include kidney and liver before is useful for bones.