Vitamins B1 & B12

by Martina McAtee

About Martina McAtee

Based in Florida, Martina McAtee has been writing health and fitness articles since 2003. She attended Keiser University, graduating with an Associate of Science in nursing. McAtee is currently working toward a master's degree in nursing from Florida Atlantic University.


Vitamin B1, also known as thiamine, and vitamin B12, are two of the eight essential B vitamins needed in your body. Your body does not create B1 or B12, so you must consume them in foods. Your body uses B vitamins to help metabolize proteins and fats for energy and to keep hair, skin, liver and eyes healthy. Deficiencies of B1 and B12 can affect every system within your body.


Thiamine is essential for the proper functioning of your heart, muscles and nervous system. This essential nutrient also assists with the flow of electrolytes in and out of muscle and nerve cells and contributes to the creation of hydrochloric acid for proper digestion. The University of Maryland explains that thiamine may also strengthen the immune system. According to the Institute of Medicine, adults should consume about 1.1 to 1.2 milligrams of thiamine a day. Every cell within your body uses B12. Vitamin B12 aids in tissue and cellular repair, nerve function, creation of red blood cells and DNA synthesis, and the breakdown of carbohydrates. Most adults need 2.4 micrograms of B12 a day.

B1 and B12 Deficiencies

Manufacturers fortify many foods with vitamins, so a thiamine deficiency, also known as beriberi, is rare in the United States, according to the National Institutes of Health. Beriberi occurs most often in chronic alcoholics due to a combination of poor nutrition and excess alcohol which makes thiamine absorption harder. The body has the ability to store B12 in the liver for three to five years, according to Merck Manual. A diet lacking in B12 can, over time, lead to a deficiency. Diseases that cause malabsorption, such as Crohn’s disease, cystic fibrosis and celiac disease can also cause a B12 deficiency. A lack of intrinsic factor, a substance that binds to foods so that the small intestine can properly break them down for nutrients, can also lead to a B12 deficiency.


Symptoms of a thiamine deficiency can often include loss of muscle and leg paralysis, pain, strange eye movements, vomiting, tingling, difficulty walking and loss of sensation in the extremities. If a B12 deficiency is in the early stages, you may exhibit no symptoms. Later, you may experience pale skin, fatigue, shortness of breath, pain, numbness and tingling of the arms, hands, feet and toes. Severe deficiencies can cause loss of balance, depression, confusion and dementia, according to the National Institutes of Health.


Thiamine deficiencies can cause life-threatening complications such as coma, death, congestive heart failure and psychosis. B12 deficiencies can lead to a lack of red blood cells called anemia. Red blood cells contain hemoglobin which assists in transporting oxygen to the tissues and organs. The National Institutes of Health explains that a lack of B12 can also lead to damage to the peripheral nervous system leading to a condition known as peripheral neuropathy.

Food Sources

It's easy to meet your thiamine needs, because it is available in a wide variety of foods. The National Institutes of Health explains that fruits, vegetables and dairy products contain a significant source of thiamine per serving, and many processed grains are fortified with thiamine. Vitamin B12 is only found in animal products, like eggs, poultry, meat and milk, according to the University of Maryland Medical Center. If you do not eat any meat or animal products, you need to consume plant foods fortified with B12 to meet your needs.

Photo Credits:

  • Images

This article reflects the views of the writer and does not necessarily reflect the views of Jillian Michaels or