Chromium appears to be safe when taken at a dosage of 50 to 200 mcg daily. 24 Side effects appear to be rare. However, chromium is a heavy metal and might conceivably build up and cause problems if taken to excess. It would be advisable to seek medical supervision if you want to take more than 200 mcg daily. Also, keep in mind that if you have diabetes and chromium is effective, you may need to cut down your dosage of any medication you take for diabetes.
Medical supervision is advised.
There has been one report of a severe skin reaction caused by chromium picolinate. 27 Concerns have also been raised over the use of the picolinate form of chromium in individuals suffering from affective or psychotic disorders, because picolinic acids can change the levels of neurotransmitters. The maximum safe dosages of chromium for young children, women who are pregnant or nursing, or those with severe liver or kidney disease have not been established. You should also separate your chromium supplement and your doses of these substances by at least 2 hours, because they may interfere with chromium's absorption. 3 Seaborn C and Stoecker B. Effects of antacid or ascorbic acid on tissue accumulation and urinary excretion of chromium.