Serious side effects from too much vitamin C are very rare, because the body cannot store the vitamin. However, amounts greater than 2,000 mg/day are not recommended because such high doses can lead to stomach upset and diarrhea.
Too little vitamin C can lead to signs and symptoms of deficiency, including:
- Bleeding gums
- Decreased ability to fight infection
- Decreased wound-healing rate
- Dry and splitting hair
- Easy bruising
- Gingivitis (inflammation of the gums)
- Possible weight gain because of slowed metabolism
- Rough, dry, scaly skin
- Swollen and painful joints
- Weakened tooth enamel
A severe form of vitamin C deficiency is known as scurvy, which mainly affects older, malnourished adults.