Over a year ago, Dr. Gerry Schwalfenberg of the University of Alberta reported in the Journal of Environmental and Public Health that he treated a case of idiopathic thrombocytopenic purpura by prescribing 4,000 IU of vitamin D/day.
Idiopathic thrombocytopenic purpura (ITP) is characterized by a low platelet count with normal bone marrow. Platelets help the body with hemostasis, a process to make sure that damaged blood vessels stop bleeding. Since people with ITP have a low platelet count, they have trouble managing bleeding. Signs of ITP include excessive bleeding nose and gums and a purpura rash on the skin.
ITP is likely an autoimmune disorder where antibodies attack platelets, though it is not known for certain. The cause of ITP is not known. It affects only 2-3 people out of every 100,000 persons. The goal of treating ITP is to keep platelet count above the lower threshold.
Now, in the most recent issue of Journal of Medical Case Reports, Dr. Barry Bockow reports on two new cases of ITP in which vitamin D played a large hand in treating and managing.
The first case was a 79 year old man who was referred to Dr. Bockow’s rheumatology clinic because traditional treatment was ineffective at raising his platelet count. The previous doctors placed him on WinRho and high-dose prednisone, and his platelet count only increased from 9,000/mm³ to 43,000/mm³ (normal is above 140,000/mm³).
The patient was placed on Plaquenil (hydroxychloroquine) 200 mg twice a day, prednisone 15 mg/day and high-dose vitamin D 50,000IU once a week. After two weeks, the platelet count only increased to 55,000/mm³. So the doctors lowered the prednisone (10 mg/day) and increased vitamin D intake to 150,000/week (kept Plaquenil the same). After two months, the patient’s platelet count increased to 114,000/mm³.
The patient remained on vitamin D for 6 months and his platelet count stabilized (140,000/mm³). The doctors then discontinued his vitamin D regimen and his platelet count dropped to 18,000/mm³. So the doctors once again placed him on vitamin D, and his platelet count increased again. After 6 months, the doctors were able to take the patient off prednisone while remaining on Plaquenil and vitamin D. His platelet count was normal and healthy.
In the second case, the doctors describe a similar story about an 87 year old woman who presented to their clinic with a low platelet count (8,000/mm³) and ITP. She was also placed on Plaquenil, prednisone and vitamin D, all in strengths similar to the first case. The doctors noted that after initial high doses, the patient’s platelet count has remained stable on Plaquenil (200 mg/day), prednisone (2 mg/day) and vitamin D (50,000 IU/month).
Dr. Bockow notes that vitamin D plays a hand in the immune system, and research is increasingly uncovering new roles and effects of vitamin D on the immune system. Doctors are hopeful that vitamin D can play a therapeutic role in autoimmune diseases, where the body’s own immune system attacks itself. In ITP, vitamin D may work by reducing the autoantibody response against platelets, thus helping keeping platelet levels in the normal range.
There are obvious limitations in case reports in that it’s not entirely clear the true effect of an intervention or if the treatment is generalizable to an entire population of patients. The researchers conclude,
“In our experience the therapeutic dose (of vitamin D) varies between 50,000 and 100,000 IU/week depending on the platelet count… We believe there is a synergistic effect of Plaquenil (hydroxychloroquine) and high-dose vitamin D that is clinically important and thus recommend further studies be done to confirm our findings and elucidate the mechanism of this interaction.”