Light · Protocol 4 of 5
Let sunshine reach your skin, safely
1In 30 seconds
On at least three days a week, and ideally daily, spend 20 to 30 minutes outside with some arms and legs uncovered. Sunlight on skin makes vitamin D and may help mood, pain and hormones. In India’s strong sun, pick gentler hours and never let your skin burn.
2Picture it
3Why do it
- 1
Ultraviolet B light on your skin starts the making of vitamin D, which you need for strong bones and a healthy immune system.
- 2
Moderate sun has been linked with better mood and less pain; in one hospital study, patients in sunnier rooms needed 22 per cent less pain medicine.
- 3
Sunlight is the richest source of red and infrared light, which may help the energy factories in your cells work better.
4How to do it
- Check the UV index for your city on a weather app before you go out, and plan your time around it.
- Spend 20 to 30 minutes outdoors, at least three days a week and ideally every day.
- Uncover as much skin as is comfortable and suitable for where you are, such as forearms, lower legs and face; a short-sleeved top works well.
- Leave the hat off for this short session when the UV index is low, but use shade, a hat or long sleeves once it climbs high.
- Go indoors well before your skin turns pink or feels hot or tight, since any sunburn damages your skin cells.
- For longer spells in strong sun, cover up with clothing or use a mineral sunscreen with zinc oxide as its active ingredient.
5Make it work in India
- In Delhi and much of India, the UV index often reaches very high or extreme levels from late morning to mid-afternoon for much of the year. In summer, aim for roughly before 9 a.m. or after 4 p.m., and check the UV index first.
- Vitamin D deficiency is very common in India despite the sunshine, because many people stay indoors, cover most of their skin, and darker skin needs longer to make vitamin D. Ask your doctor about a simple blood test.
- In peak summer, heat can be a bigger danger than burning, so keep sessions short and carry water. On severe smog days in winter, a sunny balcony is wiser than a long outdoor walk.
6The long read: the science2 min read · tap to open
Sunlight is a full mix of colours, from ultraviolet through visible light into infrared. No indoor bulb copies that mix, and each part seems to do a different job in the body.
Ultraviolet B light starts the making of vitamin D in your skin. Vitamin D helps you absorb calcium and supports bones and immunity, and it also acts like a hormone. In mice, daily UVB raised sex hormones and interest in mating. A matching study in people found more romantic interest and higher testosterone after time in the sun. The effect seemed to run through a protein called p53 in skin cells, which suggests the skin itself is sensing light.
At the other end of the spectrum, red and infrared light can travel deep into the body. It is thought to help mitochondria, the tiny power stations in your cells, make energy more efficiently and cope with the harmful by-products of that work.
The catch is that UV carries a lot of energy. Too much breaks the DNA in skin cells, ages skin early and can lead to skin cancer. Sunburn is the clear sign you have gone too far. Darker skin burns less easily, but it can still burn and still develop skin cancer.
So the goal is a dose, not a tan. Large Swedish studies found that women who got the most sun lived longer than those who avoided it, though more outdoor time also means more walking and fresh air. Sun on your skin seems helpful, but only below the burning point.
Early evidence Sunlight’s role in making vitamin D is well proven, but the claims about hormones, pain and longer life come mostly from mouse studies and observational data that cannot prove cause.
Questions people ask
Can I just take a vitamin D tablet instead?
Tablets can fix low vitamin D, and many people in India need them, so ask your doctor. But sunlight also brings red and infrared light and other effects that a tablet cannot copy.
Does sunlight through a window count?
Not really. Glass blocks most UVB, so you will not make vitamin D indoors. A bright room still helps your eyes and mood a little.
I have brown skin. Do I need to worry about sunburn?
Yes, though less. Darker skin has more natural protection, but it can still burn, age early and develop skin cancer, especially when the UV index is high.
7Be careful
Avoid sunburn at all costs, and remember India’s midday UV is often extreme, so short sessions at gentler hours are safest; never use tanning beds. Talk to your doctor first if you have had skin cancer, have many moles, have a light-sensitive condition such as lupus, or take medicines that make skin sun-sensitive, such as some antibiotics and acne treatments. See a dermatologist about any mole or patch that changes, bleeds or will not heal.
8Try it for 7 days
Tap a day each time you sun on skin, no burn.
From the book: “Expose Your Upper and Lower Body Skin to Sunlight During the Day” (Light Protocol 4). Evidence rating and India notes are our own.