Question: what vitamins and minerals interfere with each other?
Answer: Vitamin D and calcium. Like most nutrients, calcium is absorbed primarily in the small intestine. ... 
Sodium and potassium. About 90% of the sodium we ingest comes in the form of sodium chloride — salt, in common parlance. ... 
Vitamin B12 and folate. ... 
Zinc and copper. ... 
Niacin and tryptophan.