This is a hard question to answer without knowing why your white blood cell count is low or what other medical problems you have. The white blood cells are required for fighting off infections, and when they drop too low, this puts a person at risk of many different types of infections.
White blood cell counts may be low for different reasons. For example, infections with various viruses can cause the white cell counts to drop. Sometimes this is transient (for example with different common viruses) but it may be permanent and serious, such as occurs with HIV infection. In this latter case, the treatment for the low white blood cells is treating the HIV with medications.
Another common cause of low white counts is chemotherapy
medications that are used in the treatments of various types of cancer. In this situation, the drugs themselves kill off the white blood cells. Usually people with chemotherapy have to take special medications to prevent infections while they have low counts, and they many also need additional medications to stimulate the production of white blood cells.
Talk to your doctor
about your concerns. No doubt increasing your white blood cell count will first require identifying the cause for the low count.