###Human: Why do I have leg pain when I stop taking vitamin D3 supplements? ###Assistant: Hello. It appears that you have myalgia. I suggest that you take You need to drink eight to 10 glasses of water daily. Usually, vitamin D has to be taken along with calcium supplements even if the calcium levels are normal. Also, 50000 IU of vitamin D can cause muscle pain. Dehydration can also cause muscle pain and high uric acid levels. For more information consult an endocrinologist online -->