The Chennai paradox
Chennai has bright sun on most days, yet many residents show low vitamin D. The common reason is a long indoor day with little direct sun on skin. This guide explains how much sun is useful, how to stay safe, and when to test or supplement.
Tamil line: சென்னை முழு ஆண்டும் ஒளி நிறைந்த நகரம். இருந்தும் பலருக்கு வைட்டமின் D குறைபாடு உள்ளது. குறுகிய நேரம் நேரடி சூரிய ஒளி எலும்புகளை வலுப்படுத்த உதவும்.
How sunlight makes vitamin D
Sunlight has UVB rays that convert a skin molecule called seven dehydrocholesterol into vitamin D3. The liver and kidney change it into the active forms that help the gut absorb calcium and keep bones strong. Glass blocks UVB, so sunlight through windows does not help much.
How much sunlight is useful in Chennai
Simple starting plan
- Two to four days a week
- Short midday window works best for UVB in Chennai
- Expose forearms and legs if comfortable
Practical range: ten to thirty minutes in the midday window, adjusted for skin tone, age and comfort. Darker skin often needs the longer end of this range.
This is a simple public guide. Your own needs vary with skin tone, clothing, cloud cover, pollution and health conditions.
| Group | Suggested range |
|---|---|
| Adults with lighter skin | ten to fifteen minutes |
| Adults with medium to darker skin | fifteen to thirty minutes |
| Seniors | shorter bouts with rest in shade |
| Office workers | short walk near lunch time |
Local months: January to April and July to September are often comfortable for brief outdoor time. Even in other months, a short shade break between small bouts works well.
Safety and comfort in our climate
- Do not wait till skin turns red or feels sore
- Use a hat and keep the face shaded if you like
- Sunscreen reduces UVB on skin. If you use sunscreen, apply it after a very short unprotected exposure or keep a small area without sunscreen for a brief time
- Hydrate well and rest in shade. Two short outings are easier than one long one
Tips for seniors, office workers and families
Seniors and caregivers
- Choose a safe walkway near home during late morning
- Use a stable slipper with grip. Carry water. Sit in shade if needed
- Add gentle leg strength work three days a week. Strong legs reduce falls
Office and indoor workers
- Short walk near lunch time works best for UVB
- Skip glass covered corridors. Direct outdoor light is needed
- Set a calendar reminder on workdays
Women and modest clothing
- Expose forearms if comfortable. A short session still helps
- Pair with calcium rich foods and regular activity
Children and teens
- Outdoor play time on most days is ideal
- Avoid the hottest stretch. Keep it short and hydrated
When to test and when to supplement
Consider a vitamin D blood test if you have bone pain, frequent muscle cramps, low mood with fatigue, a recent fragility fracture, or very limited outdoor time. Seniors and people with osteoporosis often benefit from testing. Supplement only if advised after a review. More is not always better.
Safe next step: If you work indoors or have ongoing joint pain, book a simple bone health review. We will decide on testing, sunlight plan and diet together.
Made for our neighbourhoods
Guidance here is written for families in Thirumullaivoyal, Ambattur, Avadi, Annanur and Iyyapakkam. Our weather has strong sunlight and high humidity. Short and regular outdoor time is better than long and rare outings.
Concerned about vitamin D or bone pain
Visit OrthoCure Bone and Joint Speciality Clinic, Thirumullaivoyal. Meet Dr Sumesh Subramanian for a calm review and a simple plan you can follow.
Tamil line: வைட்டமின் D அல்லது எலும்பு வலி பற்றிக் கவலை உள்ளதா. அமைதியான பரிசோதனை மற்றும் எளிய திட்டத்திற்காக எங்களை அணுகுங்கள்.
Related reading
PEACE and LOVE for injury care Early signs of arthritis OrthoCure Bone and Joint Speciality Clinic, Thirumullaivoyal
Common questions
Does sunlight through a window help vitamin D
What is a simple plan for a busy office day
Should I use sunscreen
When should I take supplements
Medical safety This page gives general education. It is not a diagnosis. Your care plan may differ. If you have a skin condition, photosensitivity, or are on special medicines, please review before changing your routine.