Could taken vitamin d 50000, one a week for 7 weeks, last one 2 weeks ago ,be causing my knee pain?

It partially depends: upon what your current level is. Most people who take 50000 IU weekly, always under a doctor's supervision, are being treated for vitamin D deficiency. So typically the higher doses are limited and targeted to correct the deficiency. Certainly there are vitamin D toxicity symptoms including weakness, fatigue, headache...rarely joint pain. Review with your prescribing physician. Good wishes:)

Unlikely: Very unlikely you could be having any signs of vitamin d toxicity at the low dose you are taking. The other issue is that systemic toxicity usually causes more diffuse symptoms than pain isolated to one knee. I would not hesitate to be seen and evaluated for your knee pain.