I take 2000 IU a day for years. Check with your Neurologist what's right for you.

Most with MS have a low vit D levels. Have you had a vitamin D test from your neurologist?

The iu # vary from 2-5,000 daily. It seems that there is no specific universal number.

My vitamin D level is good with 1000 IU daily

I take 2000 daily :) keeps my levels up.