The metaphor is more than ten years old now, but I still encounter people who talk about "vitamin" and "painkiller" products and seem to take the difference very seriously. With "painkiller" products (solving an direct and immediate customer pain) being seen as better than "vitamin" products (that are just nice to have).
When somebody tells you your product is just a vitamin please remember that it's just a metaphor. An occasionally useful metaphor when thinking about problem/solution or product/market fit — but just a metaphor.
Please don't let it rule your life. There is no sharp dividing line between solutions that are vitamins and solutions that are painkillers.
In particular one customer's vitamin product is another customer's painkiller product.
To abuse the metaphor a little - if you want to start selling Vitamin C you don't go to the gym where there are a lot of healthy people — you go find the ship of marooned sailors who are suffering from scurvy.
"Vitamin" products can have "painkiller" customers.
"Painkiller" products can have "vitamin" customers.
"Vitamin" customers can turn into "painkiller" customers as their needs change. And vice versa.
The only thing that matters is whether the business model for your product makes sense.