A vitamin D deficiency does not cause a high white blood cell count, according to Mayo Clinic and WebMD. A high white blood cell count, known as leukocytosis, occurs when the body fights infection, reacts to medication, or develops a bone marrow disease or an immune system disorder.
Conditions that cause leukocytosis include some viral and bacterial infections, acute and chronic leukemia, allergic reactions, and rheumatoid arthritis, notes Mayo Clinic. Medications including epinephrine and corticosteroids, smoking, and severe stress also cause high white blood cell counts. A vitamin D deficiency may contribute to a higher risk of death from cardiovascular disease, impaired cognitive abilities in the elderly, severe childhood asthma and cancer, notes WebMD.