in the upper abdomen
- dark urine
- yellowing of the skin or eyes
High-dose niacin should not be treated like an ordinary daily vitamin.
5. Iron Supplements
Iron is essential for producing hemoglobin and carrying oxygen through the body.
Iron supplements can be very useful when someone has confirmed iron deficiency, but taking iron when it is not needed can be harmful.
Unlike some nutrients, the body has limited ability to eliminate excess iron.
Large amounts can accumulate and potentially damage organs, including the liver. NIH guidance notes that excess iron
