The Vitamin Deficiency That Causes the Corners Of the Mouth to Crack

B-complex vitamins play a variety of roles in your health, and insufficient amounts of these vitamins in the diet can lead to symptoms like dry mouth, cracked or split lips, and cracks in the corners of your mouth. Vitamin B deficiencies can be treated by incorporating the right foods into your diet or by using the oral or injection-based supplements that are available.

According to an August 2017 study in the ‌Journal of the Academy of General Dentistry‌, several B-complex vitamins are vital to your oral health. When you're deficient in vitamins B1, B2, B3, B6 and/or B12, you may experience various oral problems, ranging from cracked lips to tongue inflammation or even ulcers in your mouth.

B-complex vitamins are usually found in the same foods and have overlapping roles in your health. This means that a deficiency in any single B-complex vitamin is likely to be accompanied by deficiencies in other B vitamins. There are eight essential vitamins that make up the B-complex family. According to the Food and Drug Administration, most people need to consume the following amounts of B-complex vitamins on a daily basis:

• 1.5 milligrams of thiamin (vitamin B1)
• 1.7 milligrams of riboflavin (vitamin B2)
• 20 milligrams of niacin (vitamin B3)
• 10 milligrams of pantothenic acid (vitamin B5)
• 2 milligrams of vitamin B6
• 300 micrograms of biotin (vitamin B7)
• 400 micrograms of folate (vitamin B9)
• 6 micrograms of vitamin B12

There are four other B-complex vitamins (B4, B8, B10 and B11) as well, but they aren't considered to be essential nutrients that you need to consume on a daily basis to stay healthy.

A deficiency in vitamins B1, B2, B3 and B12 is known to cause cracks in the corners of the mouth. This condition is specifically known as ‌angular cheilitis (‌also called ‌angular cheilosis, angular stomatitis‌ or ‌perlèche),‌ and is essentially an inflammation of the lips.

People who experience this condition will have dry, red lips that crack on one or both sides of the mouth. These cracks may be itchy and painful; they may form white scabs and even bleed. When ‌angular cheilitis‌ occurs over a long period of time, it can cause an infection.

Vitamin B deficiency and cracked lips that occur around your mouth (not just on the sides) are primarily due to lack of vitamin B1. If you have cracked lips for long periods of time, you may also experience a split lip in which one of the cracks breaks completely and begins to bleed.

While long-term treatment for this requires resolving the vitamin deficiency, more immediate treatment typically involves applying soothing ointments, like petroleum jelly, coconut oil or medicated lip balms.

Of course, cracked and split lips aren't just caused by vitamin deficiencies. They may occur for a variety of reasons, such as exposure to cold weather or bacterial or fungal infections. In many cases, cracked and split lips will go away on their own. However, if you suspect that you have an infection or that a vitamin B deficiency is causing cracked lips, you should consult your physician.

You can find B-complex vitamins in a variety of foods that come from both plant-based and animal products. If you're experiencing cracked lips or other oral symptoms of vitamin B deficiency, you can find thiamin (vitamin B1) in:

• Enriched grains and whole grains
• Legumes
• Nuts
• Meat products, particularly those made with pork
  

You can find riboflavin (vitamin B2) in:

• Eggs
• Enriched grains
• Meat products
• Milk products
• Seafood
• Spinach

You can find niacin (vitamin B3) in:

• Beans
• Enriched grains and whole grains
• Meat products
• Nuts
• Seafood

You can find vitamin B12 in:

• Dairy products
• Eggs
• Fortified cereals
• Meat products
• Seafood
• Seaweed (but only certain types)

These vitamins are important because they support the function of red blood cell formation, the nervous system and the gastrointestinal system; they also help convert food into energy.

Although the FDA recommends daily values for all of these essential nutrients, you should be aware that certain people are more likely to be vitamin B deficient. These people include:

• Older adults
• People who take certain medications regularly, like proton pump inhibitors, antibiotics and glucose-regulating medications like metformin
• People who drink alcohol frequently
• People with malabsorptive disorders — conditions that prevent them from absorbing nutrients properly
• Vegans
• Vegetarians

These individuals should be particularly conscious of their nutrient consumption and, in some cases, may need more than the recommended daily value. Integrating more foods rich in B-complex vitamins into your diet may be a good idea if you believe you are at risk for B vitamin deficiency. According to the Mayo Clinic, any food is considered to be rich in nutrients as long as it has 20 percent or more of the total recommended daily value.

If you aren't able to obtain enough essential nutrients in your diet, your doctor may recommend that you take supplements. If your deficiency is particularly severe, your doctor may even recommend an injectable version of certain B vitamin supplements.

While deficiencies in B-complex vitamins are well known to affect your oral health, they are not the only nutrients that can do so. Lack of vitamins A, C and K, as well as iron and zinc, can all cause oral side effects that range from bleeding of the gums to inflammation of the mouth and lips (known as ‌stomatitis).‌ However, it is only iron deficiency that also causes cracked and split lips like B-complex vitamin deficiencies.

Iron is important because it helps your body to produce energy and form red blood cells. It supports growth, development, wound healing and your body's immune system. Iron is also extremely important to the reproductive process.

According to the Food and Drug Administration, iron is considered a nutrient of concern — which means that many people don't get enough of it in their daily diets. Getting enough iron is particularly important for young children, pregnant people and people who are trying to become pregnant. The daily value for iron is 18 milligrams per day. You can find iron in foods that include:

• Enriched grains
• Dark green vegetables
• Legumes
• Meat products
• Seafood