What Causes Some Vegetarians to Become Nauseous and Dizzy?

Erin Coleman, R.D., L.D.
Woman not feeling well

If you're following a vegetarian diet and feeling nauseous or dizzy, you may be wondering if your diet is to blame or if a medical condition is the culprit. A variety of things can cause dizziness in vegetarians, so knowing why this is happening to you and when to seek medical attention is a must.

1. Low Iron

Iron is a key nutrient for vegetarian dieters, according to the Academy of Nutrition and Dietetics, and iron deficiency can cause you to feel lightheaded, nauseated, and dizzy. Iron deficiency anemia affects about 2 percent of men and 9 to 20 percent of U.S. women, but dizziness from iron deficiency should resolve fairly quickly after taking iron supplements. Vegetarians have increased risks for iron-deficiency anemia simply because meat is a main source of dietary iron. To avoid dizziness caused by low iron, eat plenty of iron-rich legumes, spinach, iron-fortified breakfast cereals, dark chocolate, or tofu -- or take an iron supplement. However, use caution when taking iron supplements on an empty stomach because this can lead to nausea.

2. Vitamin D Deficiency

Vitamin D is another important nutrient for vegetarians, notes the Academy of Nutrition and Dietetics -- especially those who avoid dairy foods. About 32 percent of people in the U.S. are at risk for low vitamin D, according to the Centers for Disease Control and Prevention. A 2013 review published in Medical Hypotheses reports low vitamin D appears to be associated with vertigo, a condition that causes nausea and dizziness. If your dizziness is caused by low vitamin D, it should resolve after you get levels back up to a normal range. To avoid vitamin D deficiency, add dairy foods, egg yolks, or vitamin-D enriched orange juice, soy milk, or almond milk to your vegetarian meal plan. Or, make sure vitamin D is in your multivitamin supplement. Sunlight exposure is another way to meet daily vitamin D needs.

3. Low Vitamin B12

Being deficient in vitamin B12 is another cause of dizziness and nausea in vegetarians, according to the National Heart, Lung, and Blood Institute. About 3 percent of older adults are deficient in vitamin B12, according to American Family Physician. But dizziness should resolve within a few days after seeking treatment -- which may include B12 supplements or injections. Consume plenty of dietary vitamin B12 or take a B12 supplement to lower your risk of dizziness. If your body doesn't absorb B12 properly, ask your doctor if injections are appropriate for you. Food sources of vitamin B12 for vegetarians include vitamin B12-fortified breakfast cereal, milk, yogurt, cheese, and eggs. Soymilk is often fortified with vitamin B12, but check the nutrition label to be sure.

4. Dehydration

Being dehydrated is a common cause of nausea and dizziness, notes Mayo Clinic, and vegetarians are just as much at risk for dehydration as meat eaters. Chronic dehydration is common, especially among children, but re-hydrating should only take a few hours. Dizziness should go away after you're fully re-hydrated. To be sure you're getting plenty of fluids, drink at least 11 to 16 cups of water daily, suggests Medline Plus. Make sure your urine is light yellow or clear in color, not bright yellow (often a sign of dehydration).

5. Low Blood Sugar

Regardless of which type of diet you're following, low blood sugar is a common cause of dizziness, nausea, and even fainting. If you're experiencing dizziness and are taking diabetes medications, ask your doctor to evaluate your medication dosage and meal plan. Even if you're not diabetic, skipping meals or over exercising can cause low blood sugar. Eat regular meals or snacks spaced evenly throughout the day to help keep blood sugar in check. If your blood sugar gets too low, eat a carbohydrate-containing food (such as fruit, juice yogurt, milk, legumes, or whole grains) to make dizziness go away almost immediately.

6. Medical Conditions

Woman with headache

If you're getting all essential nutrients your body needs daily, eating regular meals, and drinking plenty of water, certain medical problems may be the cause of your nausea and dizziness. According to Mayo Clinic and Medline Plus, the following medical conditions can be the reason you're feeling dizzy:

  • Migraines
  • Vertigo
  • Meniere's disease
  • Low blood pressure
  • Anxiety/panic attacks
  • Being overheated
  • Flu
  • Allergies
  • Heart problems (heart attack, stroke, or abnormal heart beat)
  • Bleeding inside the body, including in the brain
  • Inner ear infection (Labyrinthitis)
  • Multiple sclerosis
  • Brain tumor
  • Seizures

In many cases, seeking treatment for these medical conditions can help mitigate dizziness.

7. Medications

Taking certain medications is another common cause of nausea and dizziness in vegetarians. So, if you're taking any medicines, such as blood pressure or anti-seizure medicines, antidepressants, or sedatives, be sure to check the warning label to see if your symptoms are medication-related. If you stop taking medication that's causing dizziness, the condition should resolve. Talk to your doctor before discontinuing prescribed medications.

Vegetarians and Nausea and Dizziness

While vegetarians are at risk for dizziness if they have certain medical conditions, dizziness caused by diet can be prevented and treated. Any form of dizziness poses a risk for fainting, falls, and other injuries, so if you're feeling dizzy seek medical attention as soon as possible to determine the cause and appropriate treatment.

What Causes Some Vegetarians to Become Nauseous and Dizzy?