Best Time for Sunlight Exposure to Boost Vitamin D
Sun rays contain UVB. Our body uses UVB to produce Vitamin D. Without Vitamin D, our body can't absorb calcium it ingests. The amount of UVB in sun rays varies by location, time, body & other factors -
- Location - more UVB around equator
- Time of the Day - UVB levels peak around noon
- Your Age - older people generate lesser amounts of Vitamin D than younger people
- Skin Color - darker skins have lower UVB absorption i.e. less vitamin D generation
- Sunscreen - applying sunscreen may block UVB i.e. lower vitamin D synthesis
- Season
- Cloud Coverage
- Air Quality
National Institutes of Health -
5–30 minutes of sun exposure, particularly between 10 a.m. and 4 p.m., at least twice a week usually leads to sufficient vitamin D synthesis
Harvard Medical School -
10-15 minutes of sun a few times a week can generate nearly all the vitamin D we need.
UCLA Medical Center -
In Spring & Summer, about 8 to 10 minutes of sun exposure at noon produces the recommended amount of vitamin D; in winter, nearly 2 hours of sun exposure at noon is needed to produce a sufficient amount of vitamin D - a study done in Spain
A person in Miami during summer would need 3 minutes of sun exposure, the same person in Boston during winter would need 23 minutes at noon to produce enough vitamin D
UVB radiation does not penetrate glass, so exposure to sunshine indoors through a window does not produce vitamin D. Our fat cells can store vitamin D for months, you don't need to worry if there are days when you don't get enough sun exposure
Vitamin D deficiency may lead to poor bone health - increased risk of fractures with small falls, cancer, heart diseases, mental health issues, autoimmune diseases and I am sure we discover many more health issues due to vitamin D deficiency with time. Too much of sun exposure increases the risk of skin cancer.
References
- Harvard Medical School, Time for more Vitamin D
- National Institutes of Health, Vitamin D
- UCLA Health, Dr. Robert Ashley, MD on How much sunshine do I need for enough vitamin D
Disclaimer -
The content on Bluelight.com is for informational purposes only and is not a substitute for professional medical advice, diagnosis, or treatment. Always consult a qualified healthcare provider for medical concerns.