The American Academy of Family Physicians points out that while most times an increased or abnormal heartbeat is not a serious symptom, heart palpitations can be a sign of a life-threatening cardiac arrhythmia. Although there are many possible causes, a fast or irregular heartbeat can be a sign of vitamin deficiency or excessive intake of a particular vitamin.
The National Institutes of Health's Office of Dietary Supplements reports that research studies suggest that deficiencies of folate, vitamin B12 or vitamin B6 may raise levels of homocysteine in the blood, which can increase the risk of cardiovascular disease. Elevated levels of homocysteine may affect how blood flows through the vessels. Heart palpitations are a common symptom of folate deficiency.
Folate is a water-soluble B vitamin that is found naturally in dietary food sources. Certain types of medications including anticonvulsants, sedatives, diuretics and some cancer drugs can interfere with how the body metabolizes folate. Alcohol abuse, malabsorption problems in the digestive tract, pregnancy, liver disease and anemia can also affect folate metabolism.
Abnormalities in heart rhythm can be a serious symptom of vitamin D toxicity. Other signs of excessive intake of the vitamin include weakness, weight loss and confusion. According to the Office of Dietary Supplements, vitamin D toxicity is unlikely to occur from a high intake of dietary vitamin D. One exception is consuming too much cod liver oil, which contains 1,360 IUs per tablespoon. The Daily Value developed by the Food and Drug Administration is 400 IUs for healthy adults and children over the age of 4. In most cases, vitamin D toxicity occurs as a result of high intake of dietary supplements.
Iron and Vitamin C
Although iron is not a vitamin, it is a mineral essential to human health. Anemia, a condition that is often associated with low dietary intake of iron, can cause symptoms such as dizziness, weakness, shortness of breath, rapid heartbeat and heart palpitations. A deficiency of vitamin C can lead to iron deficiency anemia and its related symptoms.
Vitamin C helps the body absorb nonheme iron, which accounts for most dietary iron. Deficiencies of folic acid or vitamin B12 are other nutrient deficiencies, which can cause anemia and the symptoms associated with it, particularly during pregnancy. Iron overload is a medical condition that can contribute to heart irregularities as well.