Is the splitting at the sides of my nails simply due to dryness?

What is the reason why the sides of my fingernails frequently crack and tear? It hurts so much. I apply Vaseline in the evening.

I try to apply hand cream regularly, but there are many times I can't because I wash my hands so often. Could washing my hands frequently or using a lot of hand sanitizer be the cause?

I am wondering if it is simply dryness or if it is related to nutritional deficiency or a skin condition.