At What Age Can Kids Take Vitamin B12?

December 30, 2025 •

4 min read

According to the National Institutes of Health (NIH), a newborn infant's liver can store enough vitamin B12 to last for several months, provided the mother has adequate B12 status during pregnancy. This means that knowing at what age can kids take vitamin B12 is essential for parents, especially those with vegan or vegetarian diets, to prevent deficiency as their child grows.

Quick Summary

The appropriate age for kids to take vitamin B12 depends on their diet and health, with guidelines for all ages from infancy through adolescence provided by health authorities. For infants, adequate B12 typically comes from breastmilk or formula, while older children, particularly those on plant-based diets, may need supplements.

Key Points

Start Supplementation for Vegan Infants Around 12 Months: While breastfed babies receive B12 from their mother and formula is fortified, vegan children should begin supplementation as they transition to solid foods, typically around 12 months.
Deficiency Poses Neurological Risks: In infants and young children, low B12 can lead to serious and potentially irreversible neurological damage, developmental delays, and anemia.
Dosage Varies by Age: The recommended daily intake of B12 is 0.4 mcg for infants (0-6 months), rising to 0.9 mcg for children aged 1-3, and 1.8 mcg for ages 9-13.
Supplements are Safe but Require Consultation: B12 supplements are considered safe for children, but a healthcare provider should always be consulted for the appropriate dosage and form, especially for at-risk children.
B12 Found in Animal Products: Natural dietary sources of B12 include meat, fish, dairy, and eggs. Plant-based sources are limited unless fortified.
Signs of Deficiency Can Be Subtle: Symptoms like fatigue, irritability, poor appetite, and slow developmental progress can indicate a B12 deficiency and warrant medical evaluation.

The Importance of Vitamin B12 for Growing Children

Vitamin B12, or cobalamin, is a crucial nutrient vital for a child's growth and development. It plays a central role in several key bodily functions, including:

Brain and Nervous System Development: B12 is critical for the development of the central nervous system during infancy and early childhood. A deficiency can lead to developmental delays and, in severe cases, permanent neurological damage.
Red Blood Cell Formation: It is necessary for producing healthy red blood cells, which transport oxygen throughout the body. Low B12 can lead to megaloblastic anemia, causing fatigue and weakness.
DNA Synthesis and Metabolism: As a cofactor in DNA synthesis, B12 is essential for cell metabolism and the proliferation of rapidly dividing cells.

Recommended Daily B12 Intake by Age

The National Institutes of Health (NIH) provides specific guidelines for daily B12 intake, measured in micrograms (mcg), tailored to different age groups. While the amounts seem small, they are vital for healthy growth.


Life Stage	Recommended Amount (mcg/day)
Infants 0–6 months	0.4 mcg
Infants 7–12 months	0.5 mcg
Children 1–3 years	0.9 mcg
Children 4–8 years	1.2 mcg
Children 9–13 years	1.8 mcg
Teenagers 14–18 years	2.4 mcg

When is B12 Supplementation Necessary for Kids?

For most children with a varied diet that includes animal products, obtaining enough B12 from food is not an issue. However, some children are at higher risk of deficiency and may require supplementation.

Infants (0-12 months):

Breastfed Infants of Deficient Mothers: If a breastfeeding mother is vegan, vegetarian, or has a malabsorption issue, her breast milk may be low in B12. In these cases, infants will require supplementation, and the mother should also address her own deficiency.
Formula-fed Infants: Most infant formulas are fortified with B12, so supplementation is not typically needed unless advised by a healthcare provider.

Toddlers and Children (1+ years):

Vegan or Vegetarian Diets: For children on strict plant-based diets, supplementation is essential as B12 is primarily found in animal products. While some plant-based foods are fortified, relying on these alone can be risky.
Malabsorption Issues: Certain gastrointestinal conditions, like celiac disease, or a lack of intrinsic factor (a protein needed for B12 absorption), can prevent adequate absorption from food.
Pernicious Anemia: A rare autoimmune condition that blocks B12 absorption and requires supplementation.
Maternal Deficiency: Children born to mothers with low B12 during pregnancy may have depleted stores and require monitoring and supplementation.

Signs of a B12 Deficiency in Children

Symptoms of a B12 deficiency can be non-specific and are sometimes mistaken for other conditions. These include:

Fatigue and extreme tiredness
Irritability and apathy
Developmental delay or regression
Poor appetite and weight loss
Muscle weakness and poor motor skills
A sore, red tongue
Involuntary movements or seizures in severe cases

Choosing a B12 Supplement for Your Child

Consult a Professional: Always speak with a pediatrician or registered dietitian before starting any new supplement to ensure the correct dosage and form for your child's specific needs.
Forms: Supplements for kids are available in liquid drops, chewable tablets, or gummies. Liquid drops are often best for infants and toddlers, while chewables are suitable for older children.
Dosage: For children on plant-based diets, a supplement with a higher dose may be needed to overcome the body's limited absorption rate. For example, studies on vegan children have shown that a daily supplement of 5-10 mcg is often necessary for those aged 1-3 years.

Comparing B12 Sources: Food vs. Supplements


Feature	Food Sources (Animal Products)	Fortified Foods and Supplements
Natural Source	Naturally occurring in animal-based foods like meat, fish, eggs, and dairy.	Synthetic forms (like cyanocobalamin) or active forms (methylcobalamin) added to products.
Absorption	Depends on intrinsic factor, an efficient but limited absorption system that maxes out at 1-2 mcg per dose.	Doesn't rely on intrinsic factor for initial absorption, allowing for higher, more efficient absorption from supplements.
Dependability	Reliable for omnivorous children with a balanced diet. Risk of deficiency is low if diet is consistent.	Highly reliable for children on vegan/vegetarian diets or those with malabsorption issues.
Risks of Deficiency	Low risk unless child is vegan/vegetarian or has an absorption issue.	No risk of deficiency if supplementation is consistent. Can be easily overlooked if not part of a daily routine.
Versatility	Dependent on incorporating specific food items into meals.	Available in various forms (drops, sprays, gummies) to suit a child's age and preferences.

Conclusion

Determining at what age can kids take vitamin B12 hinges primarily on their dietary intake. For infants, the priority is ensuring the breastfeeding mother has sufficient B12 levels or that fortified formula is used. As a child transitions to solid foods, a balanced omnivorous diet usually provides enough B12. However, children on vegan or vegetarian diets, or those with underlying health issues affecting absorption, will require consistent supplementation starting around 12 months to support proper neurological development and prevent long-term health problems. Always consult with a healthcare professional to confirm the need for and dosage of any supplement.

For more in-depth information on vitamin B12, you can refer to the National Institutes of Health (NIH) Office of Dietary Supplements.

Frequently Asked Questions

If you are vegan or vegetarian, you should speak with your healthcare provider about supplementing B12 for both yourself and your breastfed infant. B12 levels in breast milk are dependent on the mother's dietary intake, and a maternal deficiency can impact the baby.

According to the NIH, children aged 1 to 3 years need 0.9 micrograms of vitamin B12 per day. For most omnivorous toddlers, this can be met through dietary sources like milk, eggs, or fortified cereals.

Good food sources of vitamin B12 include dairy products (milk, yogurt, cheese), eggs, meat, poultry, and fish. For plant-based diets, fortified foods like certain cereals, nutritional yeast, and plant milks are important sources.

Vitamin B12 is water-soluble, and the body excretes any excess, making an overdose very rare. There is no established upper limit, though extremely high doses might cause minor side effects like dizziness.

For children with selective eating habits, supplements can be a safe and effective way to ensure adequate B12 intake. Consult a pediatrician to determine if a multivitamin or a dedicated B12 supplement is appropriate.

Symptoms can be vague, but include fatigue, developmental delays, irritability, poor appetite, and anemia. A blood test ordered by a doctor can accurately determine your child's B12 status.

Supplements come in different forms, such as cyanocobalamin and methylcobalamin. Your healthcare provider can recommend the best form and format (liquid drops, gummies, or tablets) based on your child's age and health status.