<<Disclaimer:  Verify this information before applying it to your situation.>>

Muscle weakness in celiac disease could be due to mnay things including
Myasthenia gravis
lupus
Low calcium or magnesium, potassium
poor nutrition
polymyositis
neuropathy
sjogren's syngdrome( fatique)
Anemia, addison's disease
This list is not organised as to the frequency of these things occur
..
there are other inheritied muscle problems that can be seen but do not
occur in any greater frequency in CD than other conditions.
Not medical advice
Joe Murray
University of Iowa