By Lissa Gienty, ZRT Laboratory
Quick Takeaway: Studies suggest high blood levels of 25-OH vitamin D may prevent melanoma  and appropriate D levels may affect the prognosis in both primary  and metastatic melanomas.  Keep your levels in blood between 50-80 ng/dL.
Additionally, melatonin and its metabolites protect the skin from sun and help guard the DNA there when faced with the mixture of cancer-inducing ultraviolet rays and oxidation.
The Full Story
Like so many, I figured it was never going to happen to me. Until the day that one of our docs (thank you, Dr. Alison McAllister) turned to me in a meeting and said: "I really don't like the looks of that mole, and I think you should see someone."
That was the day something finally hit home, and I realized I was a perfect candidate for skin cancer.
The Odds Were Always Against Me
I have green eyes and fair skin. I grew up in Southern California and rarely wore sunscreen. I’ve burned and peeled more times than I can count. Although my skin does eventually tan, I also have moles and freckles all over. In others words, I have Skin Type II and I'm a perfect case.
And you would think I'd know better. My parents are both in the medical industry, so I can't say I was ever uninformed about the risks of sun exposure. I now work at ZRT and talk to health care providers on a daily basis, so there's another constant reminder. I even had friends, who themselves had dealt with skin cancer, who mentioned that I should have the large, uneven mole on my right temple (that I thought I was watching closely) checked out.
I didn't pay attention to any of that until the day I got the call from the dermatologist who told me, "You have melanoma. But you're in luck, because you have the good bad kind."
The Good Bad Kind of Skin Cancer?
The good bad kind of skin cancer turned out to be a melanoma in situ, which means my melanoma was just starting and was still confined to the epidermis. As one of the docs who looked at my mole said, "It's not on the highway yet. It's still in the garage." Meaning that my treatment was going to be simple. I just needed a quick surgery to remove the mole, plus a fair margin around it for safety's sake.
I elected not to go with the Mohs surgery that was recommended by the dermatologist, and I instead had my surgery with a melanoma specialist at the John Wayne Cancer Institute. His philosophy was to biopsy all around the site first to set a clear margin, and then go in and take it all out at once.
As several doctors told me, cancer doesn't like to be provoked. My mole had already been tampered with once during the diagnostic biopsy. It seemed wise not to mess with it again until all of it could be removed. The concern here is that any treatment that allows for even one or two cancer cells to break off and travel elsewhere in the body puts you at higher risk for recurrence. I was all for taking the safest route possible.
A Proactive Follow-Up Plan
Melatonin and its metabolites protect the skin from sun rays and help guard the DNA there from neoplastic tendencies...
Two years later, I now follow the advice I should have been following all along. That is, I wear sunscreen all year round and cover up with sun-protective clothing to shield my skin. I also get skin checks every three months. (Which, by the way, six months after my surgery detected another pre-cancerous mole that was getting started between my toes!)
I also now follow the advice of our naturopathic doctors who tipped me off to several cancer-protective measures that the dermatologists didn't. Dr. Allison Smith does a better job of explaining this than I do:
Vitamin D: Keep your levels in blood between 50-80 ng/dL by eating D-rich foods like mushrooms, salmon and eggs, and by supplementing with Vitamin D3 (cholecalciferol) if your levels are low. It's hard to prove anything prevents cancer; but studies suggest high blood levels of 25-OH vitamin D may prevent melanoma  and on the other side of diagnosis, appropriate D levels may affect the prognosis in both primary  and metastatic melanomas.  Blood spot is an easy and effective way to test Vitamin D levels.
Melatonin: This hormone we associate mostly with sleep is made all over the body, and the largest organ synthesizing melatonin is the skin. Melatonin and its metabolites protect the skin from sun rays and help guard the DNA there from neoplastic tendencies when faced with the mixture of cancer-inducing ultraviolet rays and oxidation. Surprised? A recent study demonstrated that topical melatonin 12.5% slathered on the skin before sun exposure protected against sunburns.  What an important little molecule!
Diurnal Rhythms: Check your diurnal cortisol and melatonin rhythms. Studies show that diurnal dysrhythmias are associated with many cancers, including skin cancer.  
Becoming a Change Agent
I must admit, the transition from being a Southern California sun worshiper took time, but I've embraced it. I've learned to love long sleeves. I have a nice collection of hats now too. And I feel smarter that I've got something more than sunscreen working for me.
I also like reminding everyone to get their skin checked, especially if you have a history that's similar to mine.
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 Australas J Dermatol. 2017 Mar 23. doi: 10.1111/ajd.12648. [Epub ahead of print] High serum vitamin D level correlates with better prognostic indicators in primary melanoma: A pilot study. Lim A1, Shayan R1, Varigos G1.
 Oncotarget. 2017 Jan 24;8(4):6873-6882. doi: 10.18632/oncotarget.14316. Vitamin D deficiency is associated with a worse prognosis in metastatic melanoma. Timerman D1, McEnery-Stonelake M2, Joyce CJ3, Nambudiri VE4, Hodi FS5, Claus EB6, Ibrahim N5,7, Lin JY4,5.
 J Dermatol Sci. 2016 Nov;84(2):178-185. doi: 10.1016/j.jdermsci.2016.08.007. Epub 2016 Aug 9. Dose dependent sun protective effect of topical melatonin: A randomized, placebo-controlled, double-blind study. Scheuer C1, Pommergaard HC2, Rosenberg J3, Gögenur I4.
 Tumour Biol. 2014 Sep;35(9):8359-68. doi: 10.1007/s13277-014-1904-2. Epub 2014 Apr 14. Running for time: circadian rhythms and melanoma. Markova-Car EP1, Jurišić D, Ilić N, Kraljević Pavelić S.
 Int J Mol Sci. 2016 Apr 26;17(5). pii: E621. doi: 10.3390/ijms17050621. Circadian Dysrhythmias, Physiological Aberrations, and the Link to Skin Cancer. Gutierrez D1, Arbesman J2.