My knees point inwards and feel tight; can bend lying down but feel like they'll snap when crouching. on vit d for deficiency. can anything else help?

Knee pain: Malalignment varus is bowing & valgus is knock knee. May be arthritis, inflammation, sprain, etc. Consider light exercise, swim, d3, calcium, glucosamine with chondroitin. Check dexa.

Requires imaging: If your symptoms persist, you need an orthopedic evaluation and at the minimum x-ray of your knees. Simple problems can be alleviated with physical therapy and a short course of anti-inflammatory pain medications.