Chromium dinicotinate glycinate, or CDG, is a form of the mineral chromium that is used for its potential health benefits. CDG binds chromium with niacin and glycine to enhance the uptake of chromium in your body and is the preferred form of supplement manufacturers due to its increased bioavailability, according to the 2008 book "Essentials of Sports Nutrition and Supplements." Despite its potential benefits, several side effects with CDG supplementation may occur. Consult your physician before taking any nutritional supplement containing chromium or chromium dinicotinate glycinate.
Once inside your body, CDG breaks down into three distinct components, chromium, niacin, and glycine. According to the Office of Dietary Supplements, the Institute of Medicine has not established a tolerable upper intake level, or UL, for chromium because there is not enough evidence related to its effects in high doses. However, the University of Maryland Medical Center states that high doses of chromium can inhibit insulin production and cause stomach irritation, itching, flushing, irregular heart rhythms and liver dysfunction.
Niacin, or vitamin B-3, is cleaved from the chromium molecule in CDG once it is absorbed by your body. Excess niacin through over-supplementation of CDG and from other sources may cause side effects, including itching or burning of the skin, headache, blurred vision, nausea, vomiting, diarrhea, heartburn and bloating. Other, more severe side effects of niacin oversupplementation include dizziness, rapid heartbeat and a yellowing of the skin, called jaundice.
For every molecule of chromium in CDG that is absorbed by your body, one molecule of glycine is also absorbed, according to the authors of "Essentials of Sports Nutrition and Supplements." Glycine is a naturally occurring amino acid in your body and is therefore generally well-tolerated, even in large amounts. However, the process of removing the glycine molecule from CDG occurs in the stomach and upper gastrointestinal tract, which can cause some digestive distress. The most common side effects of CDG supplementation include nausea, upset stomach, diarrhea and vomiting, which are usually associated with the breakdown of CDG into glycine and niacin.
According to a 2002 study published in the "Alternative Medicine Review," chromium supplements, including chromium dinicotinate glycinate, chromium supplementation appears to be safe for most individuals. However, high doses of chromium supplements may interfere with some of your body's hormones, which can cause changes in blood sugar regulation and insulin sensitivity. Chromium supplements also promote the storage of chromium in various body tissues, especially your kidneys, which may be cause for concern if you suffer from kidney disease or renal failure, although no clear connection has been established.