Rowan Jacobsen Says 10-15 Minutes of Daily Sun Can Boost Health in New Book

2 articles · Updated · Men's Health · Jun 15

Jacobsen’s new book argues moderate daily sunlight exposure can improve longevity and lower mortality, challenging blanket warnings that any unprotected sun is harmful.
Epidemiological studies he cites link regular sunlight to benefits including vitamin D production and lower blood pressure via nitric oxide, while framing sun deficiency—not routine exposure—as the bigger modern risk.
The book distinguishes chronic exposure from intense intermittent burns, saying office workers and people who get occasional beach burns face higher melanoma risk than farmers with steady outdoor exposure.
Jacobsen also argues early sunscreens blocked UVB but not UVA, helping explain why skin cancer rose alongside sunscreen use before broad-spectrum products became standard.
His practical guidance is individualized, but he says a fair-skinned person in summer may need about 10 to 15 minutes to reach a vitamin D sweet spot near 25 ng/ml, while fair-skinned people with red hair or many moles need extra caution.