Deficiency of vitamin d3. Treatement.

My baby age of 1.5 yrs he got little bit crack of RH leg then recover well after when get through the all treatments (Plaster ). again the 6 months later same thing happened & During that came to know there is problem with vit d3(Test done-41nmol/L) to have not proper calcium absorption happened . that time Dr gave some d3 improvement meditation and again presently he fell down from cycle age 2.8 and caused major fracture of left hand. presentky he is in treatment hav e one month plaster. we are very scared n not understand how to recovery this deficiency. also for his eyes is blueish which dr said might be he has osteoporosis & need to test done. can you pls advise how to proceed for further treatement.