Myasthenia Gravis

A rare autoimmune condition where antibodies disrupt communication between nerves and muscles, causing fatigable weakness — muscles that tire with use and recover with rest. It classically affects the eyes (drooping lids, double vision), face, swallowing, and limbs, and while modern treatments control it well, certain common drugs and supplements can dangerously worsen it.

Evidence synthesis: MG is driven by autoantibodies (most often against the acetylcholine receptor) that reduce signal transmission at the neuromuscular junction — a mechanism no supplement modifies, and treatment evidence rests entirely on prescription therapies (pyridostigmine, steroids, immunosuppressants, newer complement inhibitors). Magnesium is a well-documented caution in MG: it physiologically inhibits acetylcholine release, and intravenous magnesium has precipitated myasthenic crises; oral supplements carry a smaller but real risk at high doses. Vitamin D deficiency is common in MG patients on steroids, and correction is reasonable for bone health. Observational data link infections, stress, and certain medications to flare-ups, making medication review one of the highest-yield safety interventions.