Asked by: Andrew Roberts, Wicklow
No. Irregular white spots on nails (called leukonychia) are usually caused by minor impact damage to the nail bed. Nails grow slowly so this can take time to appear and even longer to fade.
White bands on nails can be associated with severe malnutrition in children or in people suffering from low blood protein, but it’s nothing to do with calcium.
Subscribe to BBC Focus magazine for fascinating new Q&As every month and follow @sciencefocusQA on Twitter for your daily dose of fun science facts.