Child Weight Not Increasing. Blood Test Showed High ALP. Was Given Vitamin D Granules. Healthy Diet. What Else Can Be Done?

Question : Hello Doctor, my daughter is 11months old. At the time of birth she was 3.010kg. During the routine checkups, she has been keeping towards the lower curve of the growth chart. As a result, in her routine doctor's visit at her 10th month(1 month back), her doctor suggested her a blood test and the result found out to be heigh ALP (Alkaline Phosphatase) levels around 850. Then, the doctor gave her the vitamid D grannuals dosage to control the ALP levels, However, now even after having taken the vitaminD granuals plan for a month. Her weight is not increasing as per the standard WHO's growth chart. And, in her last month still a decline was noticed in her weight as the the growth chart. As far as her diet is concerned, she takes monther's milk, external milk and solid diet. She consumes around 150ml a day the external (mother dairy's full cream milk). In her last routine doctor's visit, at 11th month, she was 6.7kg and her height was 69cms.Otherwise, the child is active and agile. But, we are concerned about the decline in her weight as per the standard growth chart. Please suggest ways to increase our child's weight based in the vegetarian's diet.