Toenail splitting on my left big toe

I have a question. I noticed horizontal lines running across my left big toe nail—it almost looks cracked. On the right side, there are also these tiny pits or grooves about 2mm wide. It doesn’t hurt, and I don't recall any injuries, trips, or awkward movements lately.
Could this be something serious?

In Chinese medicine, those vertical ridges on your fingernails are actually linked to the liver—it’s essentially an indicator of fluctuating liver energy. Now, don't go panicking and thinking you have a chronic disease; true illness usually takes five to seven years of sustained imbalance to manifest. Those specific lines running vertically from the base of the nail often point toward a mineral or protein deficiency, which typically ties back to how your spleen or pancreas is functioning. In these cases, tightening up your diet and staying active with regular exercise is pretty much non-negotiable.
If you notice horizontal lines stretching across the nail instead, that's a different story altogether... it usually suggests some kind of systemic toxicity. Since it takes about four to six months for a nail to fully grow out, the closer the line is to the tip, the further back in time that imbalance occurred.

Stay healthy and stay happy 👋

I have this single line running horizontally, either left-to-right or right-to-left.
It’s positioned roughly in the middle, though leaning toward the top. I actually have two lines—one main one, and another sitting just above it.
I’ve been taking vitamins for about six months now, so maybe there's a connection there.
That upper section looks dark yellow; it doesn't match the pinkish color of the bottom part.
The issue is isolated to this one finger; everything else on my hands and feet looks fine. Could an excess of vitamins cause this? I alternate between two different supplements, taking one pill a day, and I've been at it for half a year.😢
At first, I figured I just bruised it, but it keeps growing. There are also these tiny little pits, almost like small grooves, near the edge of my right thumb. I read online that white lines can signal heart or liver issues, or even skin cancer, and that green discoloration usually means an infection.