Aluminum in our diets far exceeds that from vaccines, researchers note

Throughout life, aluminum exposure from food far exceeds aluminum exposure from routine childhood vaccines, according to a review published yesterday in JAMA. Concerns about aluminum adjuvants in vaccines have endured for decades, despite many years of research spanning multiple countries that has not identified related health concerns. 

The authors, from the Vaccine Education Center at Children’s Hospital of Philadelphia, calculate that if a person received all the aluminum-containing vaccines recommended under the January 2025 US immunization schedule, their cumulative lifetime aluminum exposure from vaccines would total roughly 12 milligrams (mg). In contrast, they estimate that aluminum absorbed from dietary sources over the course of 100 years would range from 468 to 2,785 mg. Even the lowest estimate in that range is orders of magnitude larger than the lifetime amount of exposure from vaccines.

Last month, federal officials reduced the January 2025 US childhood vaccine schedule from 17 to 11 recommended vaccines, though professional societies and most US states still recommend the previous schedule.

The contrast in exposures starts early. In the first two years of life, maximum potential aluminum exposure from vaccines is 4.4 mg. Over the same period, dietary exposure ranges from 3 to 18 mg. By age 18 years, cumulative absorbed dietary exposure is estimated at 73 to 438 mg, compared with less than 8 mg from vaccines. For adults aged 19 to 100, dietary absorption ranges from 395 to 2,347 mg, compared with less than 5 mg from vaccines during the span. 

Aluminum adjuvants remain at injection site

Aluminum has been used as a vaccine adjuvant since the 1920s to enhance immune response to inactivated and subunit vaccines (subunit vaccines do not contain any live viruses, so they are considered safe for people with compromised immune systems). Vaccines licensed for use in the United States are limited to 0.85 mg of aluminum per dose. Aluminum-containing vaccines include those against hepatitis B; diphtheria, tetanus, and acellular pertussis (DTaP and Tdap); Haemophilus influenzae type b (Hib); pneumococcal, hepatitis A, human papillomavirus (HPV); and meningococcal B (MenB). 

The authors note that earlier assumptions that all injected aluminum rapidly enters the bloodstream have been replaced by evidence that aluminum adjuvants remain largely at the injection site in granulomas, where they slow the release of antigens and decrease the chance that exposure would exceed safe levels. Granulomas are small, typically benign, localized clusters of immune cells that form when the immune system tries to contain foreign substances, infections, or chronic inflammation.

Aluminum can affect the nervous system at very high levels. One example is a rare condition called dialysis encephalopathy syndrome. The disorder has occurred in some patients receiving long-term dialysis in which aluminum accumulated in their bodies, likely from contaminated dialysis fluids. 

But, note the authors, the condition’s symptoms are distinct from those of other neurologic disorders such as autism or Alzheimer’s disease, suggesting that the disease represents a specific instance of aluminum toxicity rather than a broader threat.

Dietary exposure to aluminum is constant, lifelong

Aluminum is the third most common element on the earth’s surface. It makes up 8% to 9% of the Earth’s crust and is present in air, soil, water, and food. It is also found in food and beverage containers, cookware, building materials, and water purification systems. It’s used to make paper, dyes, textiles and rocket fuels and is a component of paints and pigments, as well as many cosmetics and personal care products such as antiperspirants. 

Exposure can occur in medical settings through injections (vaccines, certain medications), oral medication (antacids, buffered aspirin), or skin contact (first-aid products).

In short, people are exposed to aluminum regularly through ingestion, inhalation, and skin absorption. The average US adult ingests an estimated 7 to 9 mg of aluminum daily through food and water. Infants are also exposed through diet. During the first 6 months of life, estimated cumulative aluminum intake is roughly 5.3 mg from breast milk, 19 mg from milk-based formula, and up to 127 mg from soy-based formula.

While dietary exposure to aluminum is constant and lifelong, only a small fraction of ingested aluminum is absorbed into the bloodstream—depending on the form of aluminum, an estimated 0.01% to 5%. Adults typically carry 30 to 50 mg of aluminum in their bodies at any given time, primarily from dietary sources, with about half that amount lodged in bones and one-quarter in lung tissue (the amount in lung tissue is attributed to inhalational exposure).

Exposure from vaccines does not harm health

Aluminum is ubiquitous in the environment, and routine immunization contributes only a small fraction to total lifetime exposure, the authors say.

“Given our understanding of how aluminum is processed; the relative levels of exposure from diet vs vaccines; and the known, untoward health effects of aluminum toxicity,” they conclude, “the evidence is reassuring that aluminum exposure from vaccines based on the January 2025 immunization schedule does not cause untoward health effects during the first few years of life or later.”