Quote Originally Posted by Steve.r View Post

But my question is, what parts of the body most absorb vit D from sunlight? Arms, legs, torso etc? How much exposure is enough when we are told that too much sun will cause melanoma?
Any skin directly exposed to sunlight may synthesise vitamin D. The number of minutes varies by the time of year, skin colour, age, and where you are. For a fair-skinned person, it’s estimated that ~ 25 minutes of sunlight on face and forearms around the middle of the day 2-3 times a week would be sufficient, in the summer months in the UK. In tropical latitudes it would be less time. For dark-skinned ( and elderly ) it would be longer.


However, dermatologists tend not to recommend deliberate sun exposure as a " safe " means of getting vitamin D.


The "D"ilemma pitches vitamin D against " safe skin ". At the very least, burning ( redness, or worse ) should be avoided. Sunburn may cause DNA damage in skin cells ( with risk of change to cancer ).


It’s not only malignant melanoma which may result from excessive sun ( and sunbed ) exposure. Other skin cancers are also increased in frequency ( " squamous carcinoma " and " basal cell carcinoma / rodent ulcer " ). Although melanoma is the most serious ( while most can be successfully treated ), these other cancers are more common.


There is a further caution - taking vitamin D in higher than recommended doses can raise calcium levels in the blood - with various effects, such as passing much urine, nausea, vomiting and headaches.


More information is available on links 1,2, and 3 in my previous post #12. There’s now concern about rickets and osteomalacia in immigrants and ethnic risk groups, especially children ( see link ).