Here's a recent article with citations. They show that corals take up vitamin c to put down skeleton and use it similarly to humans to construct cartilage.
https://www.sciencenews.org/article/corals-need-take-their-vitamin-c
Some foods include vitamin c. For example, fuel. The dose we shoot for is generally higher than most additives and foods I've seen.
Thank you for sharing that link. Unfortunately if you read it, it basically says "duhhh, Vitamin C plus corals = what the heck and also why and what and again is that a thing? And I hope it is because someone paid me money to write an article about it and somehow I did and didn't at the same time".