Severe hypophosphataemia mimicking Guillain-Barré syndrome

Summary A 42 year-old woman presented with neurological symptoms suggestive of Guillain–Barre syndrome and required ventilatory support. She was found to have severe hypophosphataemia that was corrected promptly after which her trachea was extubated. She then revealed that she had undergone a prolonged religious fast and had just started eating again when her symptoms started. Over the next 2 weeks she made a complete recovery.