FDA Proposes New Infant Formula Nutrient Limits. The Vitamin D Floor Doubles and the Iodine Minimum Triples.
A proposed rule due Nov. 2 resets iodine, vitamin A, vitamin D and manganese limits in U.S. infant formula. Comments are due March 2, 2027.
Idea in Brief
The News
The Food and Drug Administration has proposed changing the required levels of four of the 30 nutrients in infant formula: iodine, vitamin A, vitamin D and manganese. It is the agency's first comprehensive review of formula nutrients since 1998.
What Changes
The vitamin D minimum would double to 80 IU per 100 kcal, the iodine minimum would triple, the vitamin A ceiling would nearly halve and manganese would get its first maximum. Chloride, selenium, potassium and sodium stay as they are.
Why It Matters
Nothing changes on the shelf for years: FDA proposes a three-year compliance period after its full review ends. Supplementation advice for formula-fed infants should not change on the strength of a proposal.
The Food and Drug Administration has proposed new required levels for iodine, vitamin A, vitamin D and manganese in infant formula, in a proposed rule placed on public inspection Oct. 29 and scheduled for Federal Register publication on Nov. 2.
FDA calls it the first comprehensive review of infant formula nutrients since 1998, when an outside panel last assessed the full list. It is part of Operation Stork Speed, the formula initiative the Department of Health and Human Services (HHS) and FDA announced in March 2025. The proposal covers 8 of the 30 nutrients formula must contain. It would change four of them, leave four unchanged and set the rest aside for later phases.
What would change in the formula?
The proposal raises the floors for vitamin D and iodine, lowers the ceilings for vitamin A and iodine, and sets the first maximum for manganese. According to the rule text, the changes per 100 kilocalories are:
Vitamin D: from 40 to 100 IU today to 80 to 120 IU (2 to 3 micrograms), with labels switching from IU to micrograms. Iodine: from 5 to 75 micrograms to 15 to 50 micrograms. Vitamin A: from 250 to 750 IU to 70 to 120 micrograms retinol activity equivalents (about 233 to 400 IU), and only preformed vitamin A would count toward the limits. Beta-carotene would no longer count. Manganese: the minimum falls from 5 to 1 microgram, and a new maximum of 50 micrograms is added.
Chloride, selenium, potassium and sodium were also reviewed. FDA concluded their current limits still fit the evidence.
Why is FDA moving vitamin D and iodine?
The agency's case rests mainly on vitamin D. The rule's economic analysis counts only one benefit in dollars: health care costs avoided when formula-fed infants do not develop late-onset hypocalcemia from vitamin D deficiency. FDA calls that a lower bound. It cites the National Academies' adequate intake of 400 IU a day for infants and notes that no clinical deficiency has been documented in infants receiving that amount.
For iodine, the rule points to infants' small thyroid iodine stores, their high hormone turnover and their complete dependence on milk or formula. It also notes that excess iodine can cause transient hypothyroidism, especially in preterm infants, which is why the ceiling comes down as the floor goes up. For manganese, FDA says no expert body has set an infant upper limit, but cohort evidence linking excess early exposure to developmental deficits justifies a cap. For vitamin A, it cites how unpredictably infants convert beta-carotene, at 5 to 65 percent.
The biggest clinical change is vitamin D. At the proposed floor, an infant reaches 400 IU from half as much formula as the current floor requires.
Clinical Pearls
- The proposal reviews 8 of the 30 nutrients U.S. infant formula must contain and would change limits for four: iodine, vitamin A, vitamin D and manganese.
- Vitamin D would move from 40 to 100 IU per 100 kcal today to 80 to 120 IU per 100 kcal, and the label unit would change from IU to micrograms.
- Iodine would move from 5 to 75 micrograms per 100 kcal to 15 to 50 micrograms per 100 kcal.
- Only preformed vitamin A would count toward the vitamin A limits; beta-carotene would no longer count.
- Manganese would get its first maximum, 50 micrograms per 100 kcal, while the minimum falls from 5 to 1 microgram per 100 kcal.
- FDA estimates annualized benefits of $80.9 million against costs of $17.6 million (7 percent discount rate), driven by avoided late-onset hypocalcemia from vitamin D deficiency.
What do the numbers mean at the bottle?
The Script Pad's arithmetic, from the rule's figures: at today's vitamin D minimum of 40 IU per 100 kcal, a formula at the floor supplies 400 IU only after 1,000 kcal. At the proposed 80 IU minimum, it takes 500 kcal. At the proposed 120 IU maximum, it takes about 333 kcal. The range also narrows. Today's ceiling is 2.5 times the floor, and the proposed ceiling would be 1.5 times the floor.
The other changes, in percentage terms: the iodine minimum triples and its maximum falls by a third, the vitamin A minimum falls about 7 percent and its maximum about 47 percent, and the manganese minimum falls 80 percent. These are legal limits. The proposal does not report what current products contain.
FDA estimates annualized benefits of $80.9 million against annualized costs of $17.6 million at a 7 percent discount rate. By our arithmetic, benefits come to about 4.6 times costs. The costs fall on manufacturers for reformulation, relabeling and new submissions to FDA. FDA expects benefits to go disproportionately to infants enrolled in WIC, the Special Supplemental Nutrition Program for Women, Infants, and Children. It says WIC infants make up about half of formula-fed infants in the United States and are more likely to be exclusively formula-fed.
What is not in this proposal?
The rule does not touch the ingredients HHS leaders have criticized in public, such as corn syrup solids and seed oils. Keller and Heckman noted those comments when the White House began reviewing the proposal on Oct. 14. FDA asks for comment on what comes next: whether to require DHA and arachidonic acid, whether to add alpha-linolenic acid as a required nutrient, and whether current iron levels or age-specific iron requirements should change. Those are the questions most likely to reach pediatric practices through parents.
Timing matters too. A final rule would take effect 60 days after publication. FDA proposes a compliance date three years after the effective date of the final rule that completes its phased review, not this first phase. Its economic analysis assumes benefits start in 2031.
What it means in clinic
For now, nothing changes for patients. Formula on shelves meets the current limits, and vitamin D supplementation advice should follow existing guidance, not a proposal that may change before it is final. The practical step is in the docket. Pediatric groups, neonatologists who manage preterm infants and WIC clinics can comment on the vitamin D and iodine ranges and on the DHA and iron questions under docket FDA-2026-N-10832. Comments are due 120 days after publication, which by our count is March 2, 2027.
FDA has changed food standards in recent weeks too. It let salt substitutes into standardized foods from Dec. 14. For another federal change in newborn care, see our report on a model of what ending the universal hepatitis B birth dose would do to chronic infections.
Reported, fact-checked and edited by The Script Pad's editorial staff. See How we use AI.
This article is for professional education and does not replace clinical judgment. Treatment decisions should be based on the individual patient and current guidelines.
