Elias S.Sotirchos, Johns Hopkins University School of Medicine, Baltimore, MDess@jhmi.edu
Pavan Bhargava, Baltimore, MD; Peter A. Calabresi, Baltimore, MD;
Submitted February 22, 2016
We thank Dr. Avasarala for the comments on our study. [1]
African Americans are known to have lower circulating total 25-hydroxy-vitamin D (25-OH-D) levels compared to other racial groups -- a finding most likely explained by differences in skin pigmentation. [2] However, the levels of bioavailable vitamin D have been suggested as similar in African Americans compared to Caucasians due to the lower levels of vitamin D-binding protein in African Americans. [3] Notably, total 25-OH-D levels have not been shown to be associated with risk or severity of MS in African Americans. [2,4]
Our study was not powered to assess the effects of cholecalciferol supplementation in specific patient subgroups. It will be important in future studies to determine which individual patient characteristics (including racial background) are associated with a beneficial effect of cholecalciferol. This is true for all current therapies for MS, since MS is a disease with prominent pathologic and clinical heterogeneity for which there currently exists scant evidence to guide patient-specific selection of treatment (i.e. precision medicine). Ongoing vitamin-D supplementation trials will include African-American participants and these studies may help provide more information on the role of vitamin-D supplementation in this population. [5]
1. Sotirchos ES, Bhargava P, Eckstein C, et al. Safety and immunologic effects of high- vs low-dose cholecalciferol in multiple sclerosis. Neurology 2016;86:382-390.
2. Gelfand JM, Cree BA, McElroy J, et al. Vitamin D in African Americans with multiple sclerosis. Neurology 2011;76:1824-1830.
3. Powe CE, Evans MK, Wenger J, et al. Vitamin D-Binding protein and vitamin D status of black americans and white americans. N Engl J Med 2013;369:1991-2000.
4. Munger KL, Levin LI, Hollis BW, Howard NS, Ascherio A. Serum 25- hydroxyvitamin D levels and risk of multiple sclerosis. JAMA 2006;296:2832-2838.
5. Bhargava P, Cassard S, Steele SU, et al. The vitamin D to ameliorate multiple sclerosis (VIDAMS) trial: study design for a multicenter, randomized, double-blind controlled trial of vitamin D in multiple sclerosis. Contemp Clin Trials 2014;39:288-293.
For disclosures, please contact the editorial office at journal@neurology.org.
We thank Dr. Avasarala for the comments on our study. [1]
African Americans are known to have lower circulating total 25-hydroxy-vitamin D (25-OH-D) levels compared to other racial groups -- a finding most likely explained by differences in skin pigmentation. [2] However, the levels of bioavailable vitamin D have been suggested as similar in African Americans compared to Caucasians due to the lower levels of vitamin D-binding protein in African Americans. [3] Notably, total 25-OH-D levels have not been shown to be associated with risk or severity of MS in African Americans. [2,4]
Our study was not powered to assess the effects of cholecalciferol supplementation in specific patient subgroups. It will be important in future studies to determine which individual patient characteristics (including racial background) are associated with a beneficial effect of cholecalciferol. This is true for all current therapies for MS, since MS is a disease with prominent pathologic and clinical heterogeneity for which there currently exists scant evidence to guide patient-specific selection of treatment (i.e. precision medicine). Ongoing vitamin-D supplementation trials will include African-American participants and these studies may help provide more information on the role of vitamin-D supplementation in this population. [5]
1. Sotirchos ES, Bhargava P, Eckstein C, et al. Safety and immunologic effects of high- vs low-dose cholecalciferol in multiple sclerosis. Neurology 2016;86:382-390.
2. Gelfand JM, Cree BA, McElroy J, et al. Vitamin D in African Americans with multiple sclerosis. Neurology 2011;76:1824-1830.
3. Powe CE, Evans MK, Wenger J, et al. Vitamin D-Binding protein and vitamin D status of black americans and white americans. N Engl J Med 2013;369:1991-2000.
4. Munger KL, Levin LI, Hollis BW, Howard NS, Ascherio A. Serum 25- hydroxyvitamin D levels and risk of multiple sclerosis. JAMA 2006;296:2832-2838.
5. Bhargava P, Cassard S, Steele SU, et al. The vitamin D to ameliorate multiple sclerosis (VIDAMS) trial: study design for a multicenter, randomized, double-blind controlled trial of vitamin D in multiple sclerosis. Contemp Clin Trials 2014;39:288-293.
For disclosures, please contact the editorial office at journal@neurology.org.