Currently, one in five individuals will die from cigarette smoking in the United States. Though smoking rates have significantly decreased in recent years, 16 million Americans are living with a smoking-related condition. These comorbidities span from bronchitis and pneumonia to asthma, COPD and lung cancer.
Unsurprisingly, these conditions can negatively impact overall state of health and decrease quality of life. In severe lung disease, breathing becomes strained and painful as typical functioning of the lung decreases. Often, doctors will measure the severity of a lung condition by forced expiratory volume or forced vital capacity (FEV1 and FVC). Lower FEV1 and FVC scores indicate increased disease severity and poorer lung functioning, while higher scores indicate the opposite.
According to research, vitamin D status is associated with some aspects of lung functioning and health. Due to vitamin D’s role in cell regulation and apoptosis, much of this research has covered the effect of vitamin D supplementation on lung cancer. Other effects of vitamin D on the lungs and respiratory system may be related to its role in the immune system, muscle health and inflammation, though this is not been investigated as extensively. Therefore, a recent RCT evaluated the effect of long-term, bolus-dose vitamin D supplementation on lung function in a population of older adults.
Researchers included a total of 442 individuals between the ages of 50-84 from Auckland, New Zealand. The participants were randomly assigned to one of two groups: the first group received 200,000 IU for month one, followed by 100,000 IU per month for 12 months after, while the second group received an identical placebo. Demographic data as well as medical history was reported in self-administered questionnaires. In addition, blood draws were taken at baseline, month 6 and 12. Additionally, FEV1 and FVC were measured at the same intervals.
After 12 months, this is what the researchers found:
- Approximately 14% of the participants had asthma, 17% had COPD and 49% reported past or present smoking habits.
- The increase of vitamin D status from baseline to 6 and 12 months was significantly higher in the supplement group compared to the placebo group (p < 0.001).
- No cases of hypercalcemia were reported.
- FEV1 was significantly improved by vitamin D supplementation compared to the placebo, but only in those who reported a history of smoking (p = 0.03).
- This association was strengthened for smokers who were vitamin D deficient (p = 0.04) or who had asthma/COPD (p = 0.004).
The researchers concluded:
“In summary, monthly high-dose vitamin D supplementation over an average of 1.1 years, which increased serum 25(OH)D concentration by > 50 nmol/L with respect to placebo, did not improve lung function in the overall study population.”
“In subgroup analyses, we found that vitamin D supplementation improved lung function (FEV1 and FEV z -score) in ever-smokers, particularly those with vitamin D deficiency (FEV1 only) or asthma/COPD.”
The results of this study, in addition to the existing evidence on vitamin D and lung function, indicate a relationship between the two. Further investigation of vitamin D supplementation on lung function is warranted, especially in a smoking population.
Additionally, maintaining healthy vitamin D levels (between 40-80 ng/ml) are important for optimizing the health of all individuals. The Vitamin D Council recommends a regular routine of safe sun exposure, or supplementation between 5,000-10,000 IU D3 per day. For questions about vitamin D and lung health, sun exposure or supplementation, email firstname.lastname@example.org to speak with a team member.
Peterson, R. & Cannell, JJ. Vitamin D supplementation improves lung function in smokers, especially smokers with COPD or asthma. The Vitamin D Council Blog & Newsletter, 12/2017.