Methylfolate for Kids: Which dosage is safe for children?

Parents who have read about the benefits of methylfolate often want to know if it is safe for kids. While further research is pending, here’s what we know.

In 2020, the European Food Safety Authority (EFSA) reviewed the use of calcium L-methylfolate in infant formulas and baby food. It concluded that calcium L-methylfolate is safe and non-toxic. The EFSA review also confirmed that calcium L-methylfolate was bioavailable (easily absorbed) and a suitable folate source for infants and young children.¹

More recently, a 2026 preprint reported a 12-month follow-up of a randomized infant-formula trial comparing 5-MTHF-Ca with folic acid. At 12 months, weight, length and head circumference were comparable between the groups. The number of adverse events and routine hematological results also did not differ. These preliminary findings provide further support for the safety and suitability of 5-MTHF-Ca in infant formula at the studied amount. However, the study has not yet been peer reviewed and does not establish the safety of higher-dose methylfolate supplements in children.²

Folate deficiency is associated with an increased risk for depression in children, adolescents, and adults. Those low in folate may not respond adequately to antidepressant treatment.³

A 2025 multicenter study of adolescents with major depressive disorder found that response to SSRI or SNRI treatment was approximately four times more common among participants with higher rather than low serum folate levels (28.5% versus 6.7%). However, folate levels were not associated with baseline depression severity.⁴

These findings concern folate status and do not establish that methylfolate supplements treat depression in children. In a 2022 retrospective study of 412 children and adolescents with depressive disorders, neither adjunctive L-methylfolate use nor dose was significantly associated with treatment response, regardless of MTHFR C677T genotype.⁵ Controlled pediatric trials are still needed.

A 2019 retrospective chart review included 190 patients aged 7–20 years who had neuropsychiatric conditions, primarily anxiety and mood disorders. Of these, 146 received L-methylfolate calcium - 139 at 15 mg/day and seven at 7.5 mg/day - while 44 were prescribed L-methylfolate but did not take it. Many patients were also receiving other psychiatric medications, including antidepressants. Adverse events were documented in 10% of the L-methylfolate group, compared with 25% of the untreated comparison group. The most frequently reported events among those taking L-methylfolate were impaired sleep in five patients and increased anxiety in three.⁶ The authors described L-methylfolate as well tolerated, and 22.5% of treated patients had a positive subjective treatment experience. However, because the study was retrospective and non-randomized, it could not establish that L-methylfolate caused clinical improvement or reduced adverse events. Its findings also apply to medically supervised psychiatric treatment and should not be used to determine general supplement doses for children.

A larger 2022 retrospective study examined 412 children and adolescents with depressive disorders. L-methylfolate use and dose were not significantly associated with treatment response, regardless of MTHFR C677T genotype.⁷ Therefore, although the available evidence suggests that L-methylfolate may be tolerated by many young patients under medical supervision, its effectiveness for pediatric mood disorders remains uncertain.

The current Dietary Reference Intakes (DRIs) according to the Food and Nutrition Board (FNB) are:

Birth to 6 months* 65 mcg DFE*

7–12 months* 80 mcg DFE*

1–3 years 150 mcg DFE

4–8 years 200 mcg DFE

9–13 years 300 mcg DFE

14–18 years 400 mcg DFE

19+ years 400 mcg DFE

Note: These amounts refer to total daily folate intake from food and supplements combined, based on Dietary Folate Equivalents (DFE). Methylfolate supplementation should be discussed with a healthcare professional.⁸

Research has found an association between folate status and ADHD, but it has not shown that low folate causes ADHD. A 2024 systematic review of six observational studies involving 982 children found that blood levels of folate and vitamin B12 were lower, on average, in children with ADHD than in children without ADHD. However, the studies varied considerably and could not determine whether low nutrient levels preceded ADHD or whether supplementation would improve symptoms.⁹

Studies of broad-spectrum micronutrient formulas have reported some potential benefits, but these products contain many different vitamins and minerals. In a 2022 randomized trial of 135 children ages 6–12 with ADHD and irritability, clinician-rated overall improvement was more common in the micronutrient group than in the placebo group. However, the primary parent-rated symptom measure did not differ significantly between the groups. Because the formula contained 36 ingredients, the results cannot be attributed specifically to folate, vitamin B12, or methylfolate.¹⁰

Evidence for folic acid or methylfolate alone remains limited. In a small randomized trial involving 49 children, adding 5 mg of folic acid per day to methylphenidate for eight weeks did not improve ADHD symptoms, aggression, or quality of life more than placebo.¹¹ Controlled pediatric studies have not established L-methylfolate as an effective treatment for ADHD.

Although MTHFR variants are sometimes discussed in relation to ADHD, having one of these variants does not necessarily mean that a child needs methylfolate. A 2022 meta-analysis of five studies found no association between C677T and ADHD, while A1298C showed a small statistical association. However, the research examined genetic associations - not methylfolate treatment and therefore does not show that supplementation improves ADHD symptoms.¹²

A balanced diet supports children’s overall health, but nutrition should not be described as a proven treatment for ADHD. A 2026 cross-sectional study involving 1,135 children found that ADHD was associated with greater consumption of ultra-processed foods. However, the researchers emphasized that the relationship could operate in either direction: diet might influence behavior, or ADHD-related behaviors might influence food choices.¹³ Current clinical guidance recommends a balanced diet but does not recommend eliminating artificial colors or additives as a general treatment for every child with ADHD. If particular foods appear consistently related to a child’s behavior, this should be assessed individually with an appropriate healthcare professional.¹⁴

As with any supplement, large or excessive dosages can be unsafe. It is important to follow the recommended guidelines for dosing, and always discuss supplementation with your health professional first.

If you decide to try methylfolate supplements with your child, be sure to read the product label carefully. Check that it contains L-methylfolate rather than folic acid, as methylfolate is the active, bioidentical form of folate that is readily absorbed by the body. It’s also important to check that the product has been third-party tested and is free from allergens such as gluten, dairy, soy, and artificial additives.