Children enjoy new sensory experiences, so it's not too unusual to find your toddler licking her hands, the furniture or other random objects. This behavior might be because she's mimicking the family pet or trying to taste something novel, but if it's occurring repeatedly, it may be caused by a nutrient deficiency.
A deficiency in a variety of different vitamins and minerals — including B-complex vitamins, iron and zinc — may cause unusual licking behaviors in children.
Lip Licking and Nutrient Deficiencies
If you notice that your child has been licking his lips or the area around his mouth repeatedly, he may have inflamed, cracked lips or some other issue with oral health. Children who repeatedly lick their lips or areas surrounding their mouths might also have a B-complex vitamin deficiency.
So if your child is repeatedly licking his lips, he may have a vitamin B1 (thiamin) deficiency. A deficiency in this nutrient causes cracked lips or even cracks in the corners of the mouth, which is called cheilitis or cheilosis.
Other nutrients that cause cracks in the corners of the mouth when you don't get enough include vitamin B2 (riboflavin), vitamin B3 (niacin), vitamin B12 and iron. A lack of vitamins A, C and K can also cause inflammation of the mouth and lips.
Children experiencing oral side effects from nutrient deficiencies will often repeatedly lick the affected area in an attempt to soothe it — however, this is likely to aggravate the problem further. It's important to treat these symptoms as soon as possible, because they can become itchy, painful and infected if left untreated for long periods of time.
B-Complex Vitamin Nutritional Requirements
The Harvard School of Public Health explains that there are eight B-complex vitamins essential for good health. These vitamins play a variety of roles in the body, from supporting the digestive and nervous systems to helping form red blood cells. Many B-complex vitamins can be found in foods that contain seafood, meat or other animal products. Children need different amounts of each vitamin, depending on their age.
According to the National Institutes of Health, infants 6 months and younger need 0.2 milligrams of thiamin, 0.3 milligrams of riboflavin, 2 milligrams of niacin and 0.4 milligrams of vitamin B12. Between the ages of 7 and 12 months, infants need 0.3 milligrams of thiamin, 0.4 milligrams of riboflavin, 4 milligrams of niacin and 0.5 milligrams of vitamin B12.
Children between 1 and 3 years of age need 0.5 milligrams of thiamin, 0.5 milligrams of riboflavin, 6 milligrams of niacin and 0.9 milligrams of vitamin B12, while children between ages 4 and 8 need 0.6 milligrams of thiamin, 0.6 milligrams of riboflavin, 8 milligrams of niacin and 1.2 milligrams of vitamin B12. Older children between 9 and 13 years of age need 0.9 milligrams of thiamin, 0.9 milligrams of riboflavin, 12 milligrams of niacin and 1.8 milligrams of vitamin B12.
Unusual Licking Behavior in Children
If you walk into a room and find your baby licking the floor, don't consider this to be too unusual. Babies and other young children who are 24 months or younger are often still experiencing the novelty of the world.
Young children around this age range often try to understand their surroundings through sight, sound, smell and even taste, which means that your toddler licking everything can be a perfectly normal part of her development. However, an older child (between 2 and 7 years of age) behaving this way may be a sign of a condition called pica.
Pica typically presents as unusual licking or eating behavior focused on items that aren't typically considered edible, such as stones, bricks, chalk, soap, clay or soil. However, it may also simply be expressed as licking or sucking behavior, because the child may simply want to experience a certain texture in the mouth.
Although pica sounds unusual, it's often related to a nutrient deficiency and is simply a sign of this underlying condition. Children with pica may have iron deficiency anemia or a zinc deficiency. The condition often goes away once the nutrient deficiencies have been resolved. If you think your child has pica, talk to your doctor to see if a nutritional supplement might be helpful.
Iron Intake in Children
According to the National Institutes of Health, iron is essential for children's growth and development. In fact, this nutrient is so important that pregnant women need additional amounts for their developing babies.
Iron is a major component of the blood protein hemoglobin. This nutrient also helps:
- Provide oxygen to different parts of the body
- Support normal cellular functions
- Support metabolism
- Synthesize hormones
- Synthesize connective tissue
According to the National Institutes of Health, infants up to 6 months of age need 0.27 milligrams of iron per day, while older infants between 7 and 12 months need 11 milligrams per day. Young children between 1 and 3 need 7 milligrams of iron per day; children between ages 4 and 8 need 10 milligrams per day; older children between ages 9 and 13 need 10 milligrams per day.
However, if children are following a vegan or vegetarian diet, they should consume 1.8 times the recommended amounts.
Lack of iron can cause anemia, which in turn can cause gastrointestinal problems, cognitive difficulties, problems with immune system function and issues with body temperature regulation. Iron deficiency is particularly dangerous for children, because it can cause psychomotor and cognitive problems that have the potential to lead to learning difficulties.
This essentially means that the effects of iron deficiency early in life have the potential to affect children throughout life, even once they reach adulthood.
Zinc Intake in Children
Like iron, zinc is also important to growth and development. Zinc is important because it:
- Plays a role in the ability to taste and smell
- Supports DNA and protein synthesis, as well as cellular division
- Supports growth and development
- Supports immune system function
- Supports wound healing
According to the National Institutes of Health, infants up to 6 months of age need 2 milligrams of zinc per day, while young children between 7 months and 3 years of age need 3 milligrams per day. Children between ages 4 and 8 need 5 milligrams per day, and older children between ages 9 and 13 need 8 milligrams per day.
Zinc deficiency is dangerous for children because it can prevent healthy growth and impair the function of their immune systems. Long-term zinc deficiency can even delay sexual maturation.
- NCBI: "Clinical Methods: The History, Physical, and Laboratory Examinations, 3rd Edition"
- MedlinePlus: "Pica"
- Journal of International Society of Preventive and Community Dentistry: "Eating Everything Except Food (Pica): A Rare Case Report and Review"
- NCBI: StatPearls: "Pica"
- Journal of Clinical and Diagnostic Research: "Malnutrition and Its Oral Outcome – A Review"
- NIH: "Zinc: Fact Sheet for Health Professionals"
- NIH: "Iron: Fact Sheet for Health Professionals"
- Harvard T.H. Chan School of Public Health: "B Vitamins"
- NIH: "Niacin: Fact Sheet for Health Professionals"
- NIH: "Vitamin B12: Fact Sheet for Consumers"
- NIH: "Thiamin: Fact Sheet for Health Professionals"
- NIH: "Riboflavin: Fact Sheet for Health Professionals"