For the most part, you don't need to worry about vitamins making you dizzy, but there are a few exceptions. High doses of vitamin A, niacin and choline can cause dizziness, as can a folate deficiency. Medications, low blood pressure and dehydration can also make you dizzy, so talk to your doctor to be sure that the cause is accurately targeted.
Excessive Vitamin A
Vitamin A occurs naturally in two forms. Preformed vitamin A, also called retinol, is the active form that keeps your eyes, skin and immune system healthy. It comes from animal foods such as meat, fish, poultry and dairy products. The other form -- provitamin A -- includes alpha-carotene, beta-carotene and beta-cryptoxanthin, which are found in fruits and vegetables. Your body converts them into retinol when necessary; otherwise, they function as antioxidants.
Preformed vitamin A is the only type that can accumulate in your body and become toxic. For this reason, you shouldn't consume more than 10,000 international units of preformed vitamin A daily, reports the Office of Dietary Supplements.
High blood levels of preformed vitamin A can cause dizziness. Other symptoms include fatigue, nausea, headache, hair loss and blurred vision.
High-Dose Niacin Supplements
Niacin is essential for converting the foods you eat into energy, and it also helps synthesize fatty acids. Niacin must be present to ensure that more than 400 enzymes can do their jobs, which include vital roles such as regulating cellular communication and cellular death.
High-dose supplements and prescription-strength niacin often cause side effects, including dizziness. Too much niacin may also make you feel dizzy if you get up too fast from a sitting or lying position. Large doses of niacin may make your skin flush and cause a headache, upset stomach and blurry vision, reports the University of Maryland Medical Center.
Meat, poultry, fish, beans and seeds are all good sources of niacin. When your primary source of niacin is food, you don't need to worry about consuming too much.
Too Much Choline
Even though choline isn't technically a vitamin, it meets the criteria of a vitamin -- and is often described as vitamin-like -- because it's an essential nutrient that must be included in your daily diet. Lack of choline prevents nerves from working, causes muscle damage and results in an unhealthy accumulation of fat in the liver.
Women should get 425 milligrams of choline daily, while men need 550 milligrams. Some of the best sources are beef, fish, egg yolks, Brussels sprouts and broccoli. If you consume more than the upper safe intake of 3,500 milligrams daily, your blood pressure can drop low enough to make you feel dizzy. Large doses of choline can also give your body a fishy odor and cause nausea.
Be careful if you combine supplements because it's easy to consume more than you realize if you don't keep track. For example, mixing a vitamin A supplement with a multivitamin or cod liver oil, which is very high in vitamin A, will increase your risk of dizziness. Also be aware of mixing supplements with foods that are fortified with vitamin A, niacin or choline.