Different skin tones need different amounts of UV light to activate vitamin D in the skin.
UV ratings indicate risk of skin damage – but they're based on pale skin. New wrist bands designed for six different tones of skin provide a more personalised way to track safe UV exposure.
Vitamin D seems to play a protective role when the lungs are inflamed and infected.
Asthmatics given vitamin D had fewer severe attacks that needed treatment with oral medication.
Vitamin D by Shutterstock
Vitamin D is often seen as a harmless supplement to take – the more the better. But the evidence suggests a different picture.
Allergies are becoming more frequent in the western world.
Allergies are reactions caused by the immune system as it responds to environmental substances that are usually harmless. But we don't yet have a cure or the ability to prevent them from developing.