Landmark FDA Paper on Aluminum Safety in Vaccines Has Crucial Math Error

New Safety Concerns Raised About the Quantities of Aluminum in Childhood Vaccines

Summary: The U.S. Food and Drug Administration (FDA) and the Agency for Toxic Substances and Disease Registry (ATSDR), a division of the U.S. Department of Health and Human Services (HHS), have raised concerns about the negative effects of aluminum exposure in humans. Because some vaccines contain aluminum, the FDA published a paper in 2011 (Mitkus et al.) to address concerns about aluminum exposure from vaccines in infants. The paper compared the aluminum exposure from vaccines in infants to a safety limit of oral aluminum determined by the ATSDR. However, this study incorrectly based its calculations on 0.78% of oral aluminum being absorbed into the bloodstream rather than the value of 0.1% used by the ATSDR in its computations. As a result, the FDA paper assumed that nearly 8 (0.78%/0.1%) times more aluminum can safely enter the bloodstream, and this led the authors to incorrectly conclude that aluminum exposure from vaccines was well below the safety limit.

In 2011, Mitkus et al.¹ published “Updated aluminum pharmacokinetics following infant exposures through diet and vaccination” in Vaccine, which updated an analysis published earlier by Keith et al.² in 2002 that “analyzed the pharmacokinetics of aluminum for infant dietary and vaccine exposures,” and compared the resulting body burdens to those based on the minimal risk level (MRL) established by the ATSDR.³

In their analysis, Keith et al. used the MRL of 2 mg Al/kg/day for aluminum established by the ATSDR in 1999, based on Golub et al.’s 1989 aluminum lactate study. Since the ATSDR, at that time, did not account for the amount of aluminum absorbed by the gastrointestinal tract through aluminum lactate in its computations, Keith et al. relied on other studies that observed a 0.78% absorption from aluminum lactate and used that statistic in their calculations.

In 2008, the ATSDR lowered the MRL to 1 mg Al/kg/day for aluminum using a more recent aluminum lactate study. When computing the new MRL, the ATSDR included an additional modifying factor to “account for possible differences in the bioavailability of the aluminum lactate used in the Golub and Germann (2001) study and the bioavailability of aluminum from drinking water and a typical U.S. diet.” Additionally, in explaining the uncertainty factors used to derive the new MRL, the ATSDR cited studies that found “the bioavailability of aluminum from the typical U.S. diet was 0.1%.” Thus, an aluminum absorption of 0.1% was used to calculate the ATSDR’s 2008 MRL of 1 mg Al/kg/day.

Although Mitkus et al. included the ATSDR’s most recent MRL of 1 mg Al/kg/day in their computations, they used the aluminum absorption percentage of 0.78% from Keith et al.’s analysis instead of the 0.1% absorption that the 2008 ATSDR had accounted for in its computation of the new MRL. Consequently, the MRL curve calculated by Mitkus et al. is 7.8 times (0.78%/0.1%) greater than it would have been if they had used the aluminum absorption percentage that was used to calculate the ATSDR’s 2008 MRL for aluminum. Scaling down the MRL curve calculated by Mitkus et al. by a factor of 7.8 produces results that contradict the conclusions reached by Mitkus et al. concerning the safety of aluminum quantities in vaccines (Fig. 1).

Figure 1: Body burden contributions of aluminum from diet and vaccines in infants, as shown in Mitkus et al. Figure 4, with MRL based on 0.78% aluminum absorption (blue) corrected to 0.1% aluminum absorption (red).

This graph shows the aluminum body burden (i.e., estimated amount of aluminum residing in the body) for infants calculated in the FDA paper Mitkus et al.: vaccines (black), formula (green) and breastmilk (yellow).

The MRL lines (blue and red) show the aluminum safety limit (i.e., estimated maximum amount of aluminum that an infant can safely handle).

The FDA paper Mitkus et al. assumed an incorrect aluminum absorption rate of 0.78% (blue). This level appears to be safe because it is significantly higher than the vaccine (black) line.

The corrected aluminum absorption rate is 0.1% (red). The corrected level raises concerns because it is close to the vaccine (black) line, indicating the aluminum amounts in vaccines may not be safe.

References

Mitkus RJ, King DB, Hess MA, Forshee RA, Walderhaug MO. Updated aluminum pharmacokinetics following infant exposures through diet and vaccination. Vaccine. 2011 Nov 28;29(51):9538-43. https://www.ncbi.nlm.nih.gov/pubmed/22001122.
Keith LS, Jones DE, Chou CH. Aluminum toxicokinetics regarding infant diet and vaccinations. Vaccine. 2002 May 31;20 Suppl 3:S13-7. https://www.ncbi.nlm.nih.gov/pubmed/12184359.
Agency for Toxic Substances and Disease Registry (ATSDR). Toxicological profile for aluminum. Washington, D.C.: U.S. Department of Health and Human Services; 2008. https://www.atsdr.cdc.gov/toxprofiles/tp22.pdf.

Published 2020 Mar; updated 2024 Oct