Serum 25-hydroxyvitamin D (25-OHD) levels were measured in 414 (ex)-smokers older than 50 years and the link between vitamin D status and presence of COPD was assessed. The rs7041 and rs4588 variants in the vitamin D-binding gene (GC) were genotyped and their effects on 25-OHD levels were tested.In patients with COPD, 25-OHD levels correlated significantly with forced expiratory volume in 1 s (FEV1).
Compared with 31% of the smokers with normal lung function, as many as 60% and 77% of patients with GOLD (Global Initiative for Obstructive Lung Disease) stage 3 and 4 exhibited deficient 25-OHD levels lower than 20 ng/ml.
25-OHD levels were reduced by 25% in homozygous carriers of the rs7041 at-risk allele.
76% and 100% of patients with GOLD stage 3 and 4 homozygous for the rs7041 allele exhibited 25-OHD levels lower than 20 ng/ml.
Vitamin D deficiency occurs frequently in COPD and correlates with severity of COPD. The data warrant vitamin D supplementation in patients with severe COPD, especially in those carrying at-risk rs7041 variants.
Vitamin D deficiency occurs frequently in COPD and correlates with severity of COPD. The data warrant vitamin D supplementation in patients with severe COPD, especially in those carrying at-risk rs7041 variants.
References:
Vitamin D deficiency is highly prevalent in COPD and correlates with variants in the vitamin D-binding gene. Thorax 2010;65:215-220 doi:10.1136/thx.2009.120659.
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