I am now rethinking this. This article seems convincing that Vitamin C is fine in mega dose: Could Vitamin C be Dangerous? (summary/conclusion shown here):So, that means Vitamin C is useful for chromium absorption,but the increased level should not reach toxicity. Too complicate to implement in real life!
I've seen so many multivitamin softgels with Chromium Picolinate. I guess many users of those will also be taking Vitamin C, but will be unaware of this.
Just a side note - same article - thought it was amazing that: If your dog cut its paw and developed an infection, it would manufacture around 10,000 mg of vitamin C per day to fight the infection. Fido can, you can’t.The recommended daily allowance (RDA) of vitamin C is currently 60 mg/day. This represents the minimum dose of vitamin C that will prevent scurvy, and has nothing to do with optimal health. Since needs for vitamin C increase greatly with stressors including infection, smoking, or chemical exposures, it is reasonable to assume that deficiencies can exist at doses much higher than 60 mg/day. I recommend taking vitamin C to bowel tolerance (the amount of vitamin C that an individual can take without causing diarrhea) which is usually from 500 to 8,000 mg per day in divided doses, and possibly more in times of stress or illness.
It is common for scientists and practitioners alike to find that results that occur in test tubes often do not occur in the real lives of people outside the laboratory. The test tube just isn’t a good model to approximate the wisdom and complexity of a human body. Vitamin C has in fact proven safe and effective during years of clinical use.