Most food scientists and dietary experts have stopped recommending a vitamin for this and trace elements for that - there are still a few "old school" practitioners who recommend a piecemeal approach, but as you've seen, it's not terribly effective. You're on the right track with non-GMO ingredients, digestive health, etc. and you've got the idea that calcium and Vitamin D work together. However, so do all the other ingredients, nutrients, vitamins, minerals, herbs, phytonutrients, etc.. If you take them in isolation, or in small combinations, they aren't usable by the body - you're paying for them and swallowing them, but you aren't absorbing them. That's why your hair hasn't responded.
I'd like to suggest a more comprehensive approach which will be much easier and more effective, surviving digestion, increasing absorption, and giving you everything in one fell swoop. You can, and should, keep eating the way you have been (fresh foods, etc.) - but as you say, it's not enough. Even our fresh foods are up to 40% lower in nutrients than they were a generation or two ago, so it's just not physically possible to eat enough calories to get all those essential nutrients at optimal levels. I had very unhealthy hair for years - thin, limp and falling out at high levels. Now it's full and very healthy. And all my lab work is vastly improved, I never get sick, and my health profile is much rosier than 20 years ago.
You may want to rethink those health food stores with the aisles and aisles of different nutrients - they are asking you to be the food scientist and the "kitchen chemist" to combine nutrients on your own. But most of us aren't in possession of the PhD necessary to make that happen, and that's assuming you know where and how each of those products is manufactured. The only people benefiting from those many products are the people marketing them, not the consumers. The current health crisis is testament to that.
Happy to give you more info if you let me know what your goals are.