Not any more than eating enough of any other protein.
If someone is severely protein deficient, high quality protein like that in gelatin might make a difference, but the average person gets plenty of protein.
It’s the same with calcium. It would help your nails if you were totally deficient, but if your bones are falling apart, you don’t care about your nails.
To make a real difference in nail strength, treat your nails the way you treat your skin. If you moisturize your hands after you wash the dishes, for example, rub the product into the nails as well. Keep your nails out of harsh chemicals. Wear gloves to do housework.
Someone whose nails are really brittle might even wear latex gloves when washing his or her hair. Avoid nail polish and other drying nail-care products. Polish covers nail abnormality but actually makes it worse. Polish remover, even the kind without acetone, is very drying and hard on nails.
What if your nails split rather than break? Longitudinal splitting is something that occurs with age. Ridges and valleys develop, and splitting occurs along fracture lines, because the nails are drying.
Again, help for this problem lies in moisturizing. Wet the nails and cover them with Vaseline or even alpha hydroxy acid. It is not a quick fix, but must be done until the nail grows out entirely, which takes six to eight months.
The other kind of splitting, called onychoschizia, which occurs in layers at the tip of the nail, is something seen most often in chronic polishers or people who use fingernails as tools.