Having severe vitamin D deficiency may put people aged 65 years and older at more than twice the risk of having self-reported respiratory disease, according to an article published online May 6 in the Journal of the American Geriatrics Society.[1] The author Dr Hirani had in 2010 identified a similar pattern in older member of the UK population, and described it as a public health problem.[2]
Adequate vitamin D status may also be protective against non-communicable diseases[3] like diabetes, cancers, cardiovascular disease, rheumatoid arthritis and autoimmune conditions and multiple sclerosis.[4] The clinical manifestation of suboptimal vitamin D levels has a significant physical, psychological and financial impact on older people and society as a whole.[5]
However, the question remains as to whether respiratory disease is a cause rather than a consequence of low vitamin D concentrations.
Vasant Hirani, PhD, from the Department of Epidemiology and Public Health, University College London Medical School, United Kingdom, analysed the records of 2070 people (1120 women) who participated in the 2005 Health Survey for England and who were also interviewed by a nurse and had a blood sample taken.
Dr. Hirani found that after adjusting for age, sex, season, smoking status, and social class, people with less than 35 nmol/L serum 25(OH)D were more than twice as likely to report having respiratory disease (odds ratio [OR], 2.19; 95% confidence interval [CI], 1.39 – 3.45; P =.001) as those individuals with a serum level of 64 nmol/L or higher.
Individuals with intermediate serum levels also had greater risk compared with those with levels above 64 nmol/L (35.0 to 48.9 nmol/L: OR, 1.75 [95% CI, 1.11 – 2.74; P = .02]; 49.0 to 63.9 nmol/L: OR, 1.63 [95% CI, 1.04 – 2.57; P = .04]).
Prevalence of respiratory disease among the study population ranged from 8.9% for people with vitamin D levels of 75 nmol/L and greater to 45.5% for people with levels of 25.0 to 49.9 nmol/L. The association was not consistent, however, as only 14.7% of individuals with serum 25(OH)D levels lower than 25 nmol/L reported having respiratory disease.
Although Dr. Hirani found associations in unadjusted analyses between low vitamin D levels and smoking tobacco, lower social class, fair or poor general health, and self-reported heart disease, cancer, and pain, she found no associations between low vitamin D levels and age, sex, body mass index, alcohol consumption, or use of vitamin supplements.
Dr Hirani states it is “biologically plausible” for vitamin D to be associated with respiratory health”, because of vitamin D’s role in the lung’s immunity response to virus infection.
It is also likely that individuals with a respiratory condition are less likely to spend time outdoors and may also limit their activities, resulting in less sunlight exposure and thus vitamin D deficiency. More research is needed to clarify the cause and effect of the association, she notes.
Although definitive conclusions as to whether low vitamin D is truly linked to respiratory disease, she writes, the study population is nationally representative of people of that age in England.
She concludes,
“Regardless of the direction of causation, the higher-than-expected co-occurrence of vitamin D deficiency and respiratory conditions is an important public health question for older populations living in northern latitudes because both are common, and both have substantial adverse health consequences.”
Comment
Consider that Vitamin D – important as it is for immune competence, once satisfactory levels are achieved through environmental, food, or supplemental additions that the role of vitamin A in immune competence must also be considered. Why just this vitamin? – well Vitamin D and Vitamin A share the same receptor family and supplementation of either may competitively inhibit the attachment of the associated competitor leading to diminished rather than enhanced immune competence.
References
[1] Hirani V. Associations Between Vitamin D and Self-Reported Respiratory Disease in Older People from a Nationally Representative Population Survey. J Am Geriatr Soc. 2013 May 6. doi: 10.1111/jgs.12254. [Epub ahead of print] View Abstract
[2] Hirani V, Tull K, Ali A, Mindell J. Urgent action needed to improve vitamin D status among older people in England! Age Ageing. 2010 Jan;39(1):62-8 View Full Paper
[3] Holick MF. Vitamin D: importance in the prevention of cancers, type 1 diabetes, heart disease, and osteoporosis. Am J Clin Nutr 2004;79:362-71. View Full Paper
[4] Munger KL, Levin LI, Hollis BW, Howard NS. Serum 25-hydroxyvitamin D levels and risk of multiple sclerosis. JAMA 2006;296(23):2832-8. View Abstract
[5] Tuck SP, Francis RM. Best practice: osteoporosis. Postgrad Med J 2002; 78:526-32. View Abstract
