A little Sunday chat with ChatGPT 5, because Sunday football is not on yet and I feel the need to blog.
I did a ChatGPT 5 and Gemini search, paid versions, with this prompt:
“List both common and uncommon dietary supplements that have been associated with cancer development or risk in humans, through any mechanism or reported evidence. Clearly differentiate between supplements with robust evidence and those with only limited or preliminary reports. For each supplement, briefly summarize the type of association (e.g., increased risk, potential protective effect, conflicting evidence) and indicate the source or quality of evidence (e.g., meta-analysis, case reports, observational studies). Limit the output to dietary supplements with human data or strong human-relevant reports. If the evidence is particularly ambiguous or controversial, flag this clearly”.
Though there are many supplements with increased risk of cancer, it is entirely dose dependent.
I won’t list them all, but they include beta-carotene, vitamin E, vitamin B6/B12 (in smokers), calcium (high intake/supplement), multivitamins (very high use), zinc (high-dose, long-term), and comfrey tea. As the supplement list is entirely dose dependent, none have been taken off the market
Limited the list to supplements with human evidence suggesting increased cancer risk. "For lithium (including orotate), I couldn’t find human data."
The thing is, supplements taken by humans over a period of time tend to put up a red flag for cancer association. Of the supplements I listed, and there are many more, they are weak associations. Of the ones listed, only beta-carotene showed any significant association, and that was caught fairly quickly because people were taking it in high doses, especially fair-skinned people like me.
Beta-carotene is widely used as a food colorant.
“Observational studies link higher fruit/vegetable intake and higher plasma β-carotene with lower risks of lung and some other cancers, and influential papers (e.g., Peto and colleagues in 1981) propose β-carotene as a key protective factor. This, plus its role as a provitamin A antioxidant, drives widespread supplement use in the 1980s–early 1990s.”
“1994 (first clear signal of harm at high daily doses): ATBC trial. In 29,133 male smokers given 20 mg/day β-carotene, lung cancer incidence increased (≈18%) and overall mortality rose (≈8%) vs. no β-carotene after 5–8 years; this was the first large randomized evidence that high-dose daily β-carotene could increase certain cancer risks in high-risk groups.”
The highest daily dose of β-carotene supplements that I could find on Amazon was 7.5 mg/day.
“Some people did take high-dose β-carotene (me) specifically to tint their skin. The effect (carotenoderma/carotenemia) shifts skin toward yellow-orange rather than the brown of a melanin suntan. Controlled studies and reviews show that daily β-carotene can measurably change skin color within ~8–12 weeks; however, most commercial “tanning pills” historically relied on a different carotenoid (canthaxanthin), which the FDA does not approve for this use.”
Yes, silly me jumping on the beta-carotene bandwagon. Note: this was before the internet was widely used. The hype was mostly spread by various magazines, like Men’s Health.
Since I was always looking for a suntan (I don’t tan; I just burn), I took it in massive doses for several weeks. I found no subjective betterment in skin tone, so I stopped taking it. Fortunately I didn’t develop any cancers after more than thirty years.
I am only telling you this because the link and risk for you developing cancer from any supplement you take, including lithium orotate, which I have been taking for over thirty years, is very low indeed.
