Igweze et al. 2019 — Essential Trace Metals in Infant Formulae, Nigeria
This 2019 Nigerian study measured Fe, Zn, Mn, Cr, and Co (essential trace metals) in 26 commercial infant formula brands from Port Harcourt, assessing nutritional adequacy. Note: only essential trace metals measured; no toxic metals (Pb, Cd, As) reported. Cr reported as total chromium.
Key numbers
Milk-based infant formula (n=9, dry weight, mg/kg):
| Metal | Mean ± SD | Range | LOD (ppm) |
|---|---|---|---|
| Cr (total) | 0.61 ± 0.70 | 0.06–2.08 | 0.005 |
| Fe | 4.08 ± 1.95 | 2.01–8.02 | 0.010 |
| Zn | 6.71 ± 2.10 | 4.58–10.41 | 0.060 |
| Mn | 0.15 ± 0.09 | 0.04–0.34 | 0.005 |
| Co | 0.12 ± 0.32 | 0.002–0.96 | 0.005 |
Methods
AAS or ICP (not specified in excerpt). Dry weight basis. n=26 brands total; milk-based n=9.
Note: Cr reported as total chromium. HMT&C analyte for Cr is Cr-VI (hexavalent chromium), which requires separate speciation. Total Cr in infant formula (mean 0.61 mg/kg = 610 µg/kg) cannot be compared to Cr-VI limits; the vast majority of Cr in formula is likely Cr(III) from milk/lactose, not Cr(VI). Flag but do not apply HMT&C Cr-VI thresholds to these total Cr values.
Implications
Certification: Total Cr data cannot inform Cr-VI thresholds. Fe and Zn are within expected supplemented formula ranges.