Q. For years my nails have been very dry with a tendency to split. I’m allergic to the formaldehyde often used in nail care products, so I’ve been taking evening primrose oil capsules. However, my nails are now yellowing. Is this normal?

A. Doctors say the yellowing of nails is because they are growing more slowly than normal and can be attributed to a variety of health-related conditions including poor circulation. Taking evening primrose is said to help because the rich source of essential fatty acids not only prevents nails from cracking but also helps to keep them generally healthy. Doctors also recommend taking 800 international units (IU) of vitamin E daily (but check with your doctor first), or rubbing vitamin E oil directly into the nail itself. However, if this doesn’t seem to help and you don’t see any improvement, talk to your doctor.