Do you mean you were tested for all those and your levels were normal? If so, I can understand why they said that. But, if they don’t know the levels…..I’d be curious about the reasoning. I had no idea that I was not absorbing B12. I had developed substantial damage as a result. So diet and even oral vit B12 won’t help me.
Also, years ago I was diagnosed with Vit D deficiency. I now take supplements, because I need it. Low level Vit D can cause severe problems. My doctors have ordered this. So, it’s not up to my nutritionist. I value my nutritionists. I have two, but they are not physicians.

I take prenatal vitamin, D, super B12 & biotin. Zinc, Selenium & vitamin C - I wonder why a nutritionist told you get off vitamins & get them e food intake. Did she give you a sheet w vitamin provision options? I can't afford to get sick or have a vitamin deficiency. Best to you