Signs & Symptoms of Excess Vitamin D

Vitamin D is an essential vitamin for humans, but it is found naturally in few food sources. Most people get most of their vitamin D from sunlight and fortified dairy products, but it also is available in nutritional supplements. The Institute of Medicine recommends a daily intake of 200 IUs of vitamin D for children and adults up to age 50, and 400 to 600 IUs for adults 50 and older. However, those recommendations likely will be revised upward because many experts believe people need more vitamin D on a daily basis, according to Mayo Clinic. Too much vitamin D can be serious, but the condition is rare, even in people who take supplements.

Gastrointestinal Symptoms

• Getting too much vitamin D can cause a variety of gastrointestinal symptoms, including nausea, vomiting and loss of appetite. Some people also can develop constipation when too much of the vitamin is consumed. These symptoms develop because excess vitamin D causes too much calcium to build up in the blood, according to the Mayo Clinic.

Cardiac Symptoms

• As blood calcium levels rise because of excessive vitamin D intake, your heart can develop abnormalities in its rhythm, according to the National Institutes of Health. These abnormalities, called arrhythmias, can affect the heart rate and the heart rhythm. Some people can experience heart palpitations, which can cause symptoms such as dizziness and lightheadedness.

Other Symptoms

• Other signs of excess vitamin D in the body include mental confusion, weakness and kidney stones. Similar to other symptoms, these signs are caused by a build-up of calcium in the blood, a condition called hypercalcemia.

Treatment

• The first step in treating vitamin D toxicity is stopping the excess consumption of the vitamin and temporarily restricting other sources of calcium in the diet. In severe cases, patients might need to be hospitalized to receive intravenous fluids and other treatments to reduce blood calcium levels.