You finally finished repainting those end tables for the guest room. As you’re washing up, you notice something on your fingernail. You try to scrub it off and realize the little white dots are not paint; they’re actually part of your nail.

You show the spots to your roommate and he says it could mean you have a calcium deficiency. Or wait, is it zinc? It’s definitely some sort of nutritional deficit, of that he’s certain. But you start to wonder if he’s right because just last month, he told you that washing your face in egg whites will decrease the size of your pores. However, when you mentioned that to your dermatologist, she said that nothing can actually shrink your pores. So what are these white spots and how’d you get them?

One of the most common causes for these little white spots, which can show up on both fingernails and toenails, is a condition called leukonychia. Although the name sounds pretty serious, the condition typically isn’t. And while many people think they’re caused by a calcium or zinc deficiency, that’s generally not the case.

In reality, these spots most often develop as a result of mild to moderate trauma to your nail. If you can’t think of anything that would have injured your nail, consider the fact that nails grow very slowly, so the injury may have occurred weeks before the spots ever appeared. Another possibility is that the spots could be a sign of a mild infection or allergy, or a side effect of certain medications.

Whatever the source of the injury, these spots typically do not require any treatment and should go away as your nail grows out. And they should not return unless you suffer another nail trauma. However, this generally applies when only a single or a few nails are affected. If all of your nails are showing white spots or streaks, the leukonychia could be related to another more serious condition such as anemia, cardiac disease, cirrhosis, diabetes or kidney disease. Overall, it’s good practice to pay attention to changes and abnormalities in your fingernails and to consult your doctor if you’re concerned.