Iron status indicators and categories at 12 months of age
| Control (n=59) | BLISS (n=60) | Difference (95% CI)* | P values | |
| Haemoglobin (g/dL), mean (SD) | 11.7 (0.84) | 11.6 (0.89) | −0.08 (−0.40 to 0.23) | 0.59 |
| Plasma ferritin (μg/L)† | 28.9 (18.5, 47.4) | 27.0 (19.5, 42.1) | −2.6 (−10.9 to 5.8) | 0.55 |
| Soluble transferrin receptor (mg/L), mean (SD) | 7.6 (2.0) | 7.4 (2.7) | −0.2 (−1.0 to 0.7) | 0.70 |
| Body iron (mg/kg)‡, mean (SD) | 3.3 (3.1) | 3.3 (2.9) | 0.04 (−1.1 to 1.2) | 0.95 |
| C-reactive protein (mg/L) | 0.1 (0.0, 0.5) | 0.2 (0.1, 0.5) | −0.02 (−0.2 to 0.2) | 0.86 |
| α1-Acid glycoprotein (g/L) | 0.6 (0.4, 0.8) | 0.6 (0.5, 0.95) | 0.04 (−0.1 to 0.2) | 0.56 |
| Iron status categories, n (%) | OR (95% CI)§ | P values | ||
| Iron sufficient¶ | 49 (83) | 50 (83) | 1.0 | – |
| Iron depleted** | 3 (5) | 2 (3) | 1.5 (0.2 to 9.6) | 0.65 |
| Early functional iron deficiency†† | 4 (7) | 4 (7) | 1.0 (0.2 to 4.3) | 0.98 |
| Iron deficiency anaemia‡‡ | 3 (5) | 4 (7) | 0.8 (0.2 to 3.6) | 0.74 |
Data presented as median (25th, 75th percentile), unless otherwise stated.
*Difference adjusted for infant age (in days) and sex, and maternal education and parity: negative values represent lower values in BLISS than in control, positive values represent higher values in BLISS than in control.
†Ferritin adjusted for inflammation using multipliers proposed by Thurnham et al.21
‡Body iron calculation (mg/kg)=−[log10(sTfRx1000/ferritin)−2.8229]/0.1207 from Cogswell et al. 22
§OR of control relative to BLISS.
¶Defined as body iron ≥0 mg/kg, haemoglobin ≥11.0 g/dL and plasma ferritin ≥15 µg/L.
**Defined as plasma ferritin <15 µg/L, in the absence of early functional iron deficiency and iron deficiency anaemia.
††Defined as body iron <0 mg/kg and haemoglobin ≥11.0 g/dL.
‡‡Defined as body iron <0 mg/kg and haemoglobin <11.0 g/dL.
BLISS, Baby-Led Introduction to SolidS.