Dr. Michael F. Holick, Ph.D., M.D.
Dr. Michael F. Holick

Dr. Holick’s Responses to Participant Questions During the December 5, 2008 Live Webinar Presentation “Vitamin D & Chronic Disease Risk”

Posted by mfholick on March 6, 2009 under Cancer, Multiple Sclerosis, Osteomalacia, Osteoporosis, Rickets, Vitamin D | 62 Comments to Read





I have heard that vitamin D may play a role in epilepsy, possibly due to interaction with anti-epileptic drugs.  Is this becoming an acknowledged effect?  And how much vitamin D is necessary to combat the interaction to reduce seizures?

Response:  Epileptic drugs will enhance the destruction of vitamin D making patients who are on anti-seizure medications at higher risk for developing vitamin D deficiency and osteomalacia or rickets.  Measurement of 25-hydroxyvitamin D [25(OH)D] is important in patients on antiepileptic medications.  Often twice as much vitamin D is required to maintain a blood level of  25(OH)D of > 30 ng/ml.  Thus, 2,000-4,000 IU of vitamin D/d is usually needed.  An alternative is to take 50,000 IU of vitamin D2 either once every week or once every two weeks depending on the serum 25-hydroxyvitamin D level.




What is your position on vitamin D and depression and schizophrenia?

Response:  There is evidence that vitamin D deficiency during pregnancy increases the risk of the child developing schizophrenia during their adult life.  There is also evidence that vitamin D receptors exist in the brain, and that the active form of vitamin D, 1,25-dihydroxyvitamin D, Read more of this article »

Rickets and Vitamin D

Posted by admin on November 27, 2008 under Rickets, Vitamin D | 2 Comments to Read

Rickets occurs at approximately six months of age in children who are vitamin D deficient.  They can present with growth retardation, skeletal deformities including bowing of the legs or knocked knees, prominent knob like projections along the ribs next to the sternum known as the rachitic rosary and muscle weakness.  Infants with vitamin D deficiency also suffer from craniotabes which is a softening of the skull causing it to become square shaped.  They can have increase in the bone formation in the front of the head which is known as frontal bossing.


Holick, M.F.  Resurrection of vitamin D deficiency and rickets.  J Clin Invest 2006, 116(8):2062-2072..

Kreiter SR, Schwartz RP, Kirkman HN, Charlton PA, Calikoglu AS, Davenport M.  Nutritional rickets in African American breast-fed infants.  J Pediatr 2000;137:2-6.

Marksted, T., Halvorsen, S., Halvorsen, K.S., Aksnes, L., and Aarskog, D.  1984. Plasma concentrations of vitamin D metabolites before and during treatment of vitamin D deficiency rickets in children.  Acta Padiatr Scand. 73:225-231.