Electronic cigarettes
National Centre for Smoking Cessation and Training

Vitamin D: increasing supplement use among at-risk groups
National Institute for Health and Care Excellence

British guideline on the management of asthma in adults
The British Thoracic Society & Scottish Intercollegiate Guidelines Network

British guideline on the management of asthma in children
The British Thoracic Society & Scottish Intercollegiate Guidelines Network

COPD diagnosis, management and prevention
Global Initiative for Chronic Obstructive Lung Disease