Both high and low serum vitamin D concentrations are associated with tuberculosis:A case-control study in Greenland

• Published in: British Journal of Nutrition
• Main Authors: Nielsen, Nina O., Skifte, Turid, Andersson, Mikael, Wohlfahrt, Jan, Sborg, Bolette, Koch, Anders, Melbye, Mads, Ladefoged, Karin
• Format: Article in Journal/Newspaper
• Language: English
• Published: 2010
• Subjects: Case-control studies; Greenland; Odds ratios; Tuberculosis; Vitamin D; greenlander*
• Online Access: https://curis.ku.dk/portal/da/publications/both-high-and-low-serum-vitamin-d-concentrations-are-associated-with-tuberculosis(78188d4c-35fa-4680-8f8a-f25f38e76d7a).html; https://doi.org/10.1017/S0007114510002333; http://www.scopus.com/inward/record.url?scp=78649982896&partnerID=8YFLogxK

Vitamin D deficiency has been associated with increased risk of tuberculosis (TB). Changes from a traditional to a Westernised diet among Greenlanders have resulted in reduced serum vitamin D, leading to considerations of whether preventive vitamin D supplementation should be introduced. The association between vitamin D status and TB was examined to assess the feasibility of vitamin D supplementation in Greenland. This was examined in a case-control study involving seventy-two matched pairs of TB patients (cases) and controls aged 8-74 years. Cases were diagnosed with TB during 2004-6 based on clinical findings in combination with either (1) positive Mycobacterium tuberculosis culture, (2) characteristic X-ray abnormalities together with a positive tuberculin skin test or a positive interferon- release assay or (3) characteristic histology. Controls were individually matched on age (±5 years), sex and district. Serum 25-hydroxyvitamin D (25(OH)D) concentrations were measured and OR of TB were the outcome. Compared with individuals with 25(OH)D concentrations between 75 and 140nmol/l, individuals with concentrations<75nmol/l (OR 65; 95% CI 18, 235) or>140nmol/l (OR 65; 95% CI 19, 222) had higher risks of active TB (P=0003; adjustment for alcohol and ethnicity). Supplementing individuals with low vitamin D to normalise serum 25(OH)D concentrations was estimated to result in a 29% reduction in the number of TB cases. The study indicated that vitamin D supplementation may be beneficial to individuals with insufficient vitamin D concentrations but may increase the risk of TB among individuals with normal or high concentrations.