### Abstract

Background: Calcium absorption is enhanced by the presence of lactose, but the quantitative significance of this effect in infant formulas is uncertain. It is also not known whether lactose affects zinc absorption. Objective: We measured the absorption of calcium and zinc from infant formulas by using a multitracer, stable-isotope technique. Design: Eighteen full-term infants (aged 8-12 wk at enrollment) were fed 2 partially hydrolyzed whey -protein-based formulas ad libitum for 2 wk per formula. The carbohydrate source was lactose in one formula and glucose polymers in the other (lactose-free). Infants were studied in a blinded crossover fashion after 2 wk of adaptation to each formula. Isotope absorption studies were conducted with a 4-tracer method in which ^{70}Zn and ^{44}Ca were provided orally and ^{67}Zn and ^{46}Ca intravenously. Zinc and calcium absorption was measured from the fractional excretion of the oral and intravenous isotopes in urine. Results: Fractional and total calcium absorption was significantly greater from the lactose-containing formula than from the lactose-free formula. For total calcium absorption, the mean difference between formulas was 10.3% (P = 0.002) and 60 mg/d (P = 0.006). For zinc, fractional absorption (32 ± 11%), total absorption, and intake did not differ significantly between the 2 formulas. Conclusions: The presence of lactose in a formula based on cow-milk protein increases absorption of calcium but not of zinc. Absorption of calcium from a lactose-free infant formula is, however, adequate to meet the calcium needs of full-term infants when the formula's calcium content is similar to that of lactose-containing, cow-milk-based infant formulas.

Original language | English (US) |
---|---|

Pages (from-to) | 442-446 |

Number of pages | 5 |

Journal | American Journal of Clinical Nutrition |

Volume | 76 |

Issue number | 2 |

State | Published - 2002 |

Externally published | Yes |

### Fingerprint

### Keywords

- Breast milk
- Calcium absorption
- Human milk
- Infant formula
- Infant nutrition
- Mass spectrometry
- Mineral requirements
- Stable isotopes
- Zinc absorption

### ASJC Scopus subject areas

- Medicine (miscellaneous)
- Food Science

### Cite this

*American Journal of Clinical Nutrition*,

*76*(2), 442-446.

**Calcium and zinc absorption from lactose-containing and lactose-free infant formulas.** / Abrams, Steven A.; Griffin, Ian J.; Davila, Penni M.

Research output: Contribution to journal › Article

*American Journal of Clinical Nutrition*, vol. 76, no. 2, pp. 442-446.

}

TY - JOUR

T1 - Calcium and zinc absorption from lactose-containing and lactose-free infant formulas

AU - Abrams, Steven A.

AU - Griffin, Ian J.

AU - Davila, Penni M.

PY - 2002

Y1 - 2002

N2 - Background: Calcium absorption is enhanced by the presence of lactose, but the quantitative significance of this effect in infant formulas is uncertain. It is also not known whether lactose affects zinc absorption. Objective: We measured the absorption of calcium and zinc from infant formulas by using a multitracer, stable-isotope technique. Design: Eighteen full-term infants (aged 8-12 wk at enrollment) were fed 2 partially hydrolyzed whey -protein-based formulas ad libitum for 2 wk per formula. The carbohydrate source was lactose in one formula and glucose polymers in the other (lactose-free). Infants were studied in a blinded crossover fashion after 2 wk of adaptation to each formula. Isotope absorption studies were conducted with a 4-tracer method in which 70Zn and 44Ca were provided orally and 67Zn and 46Ca intravenously. Zinc and calcium absorption was measured from the fractional excretion of the oral and intravenous isotopes in urine. Results: Fractional and total calcium absorption was significantly greater from the lactose-containing formula than from the lactose-free formula. For total calcium absorption, the mean difference between formulas was 10.3% (P = 0.002) and 60 mg/d (P = 0.006). For zinc, fractional absorption (32 ± 11%), total absorption, and intake did not differ significantly between the 2 formulas. Conclusions: The presence of lactose in a formula based on cow-milk protein increases absorption of calcium but not of zinc. Absorption of calcium from a lactose-free infant formula is, however, adequate to meet the calcium needs of full-term infants when the formula's calcium content is similar to that of lactose-containing, cow-milk-based infant formulas.

AB - Background: Calcium absorption is enhanced by the presence of lactose, but the quantitative significance of this effect in infant formulas is uncertain. It is also not known whether lactose affects zinc absorption. Objective: We measured the absorption of calcium and zinc from infant formulas by using a multitracer, stable-isotope technique. Design: Eighteen full-term infants (aged 8-12 wk at enrollment) were fed 2 partially hydrolyzed whey -protein-based formulas ad libitum for 2 wk per formula. The carbohydrate source was lactose in one formula and glucose polymers in the other (lactose-free). Infants were studied in a blinded crossover fashion after 2 wk of adaptation to each formula. Isotope absorption studies were conducted with a 4-tracer method in which 70Zn and 44Ca were provided orally and 67Zn and 46Ca intravenously. Zinc and calcium absorption was measured from the fractional excretion of the oral and intravenous isotopes in urine. Results: Fractional and total calcium absorption was significantly greater from the lactose-containing formula than from the lactose-free formula. For total calcium absorption, the mean difference between formulas was 10.3% (P = 0.002) and 60 mg/d (P = 0.006). For zinc, fractional absorption (32 ± 11%), total absorption, and intake did not differ significantly between the 2 formulas. Conclusions: The presence of lactose in a formula based on cow-milk protein increases absorption of calcium but not of zinc. Absorption of calcium from a lactose-free infant formula is, however, adequate to meet the calcium needs of full-term infants when the formula's calcium content is similar to that of lactose-containing, cow-milk-based infant formulas.

KW - Breast milk

KW - Calcium absorption

KW - Human milk

KW - Infant formula

KW - Infant nutrition

KW - Mass spectrometry

KW - Mineral requirements

KW - Stable isotopes

KW - Zinc absorption

UR - http://www.scopus.com/inward/record.url?scp=0036070706&partnerID=8YFLogxK

UR - http://www.scopus.com/inward/citedby.url?scp=0036070706&partnerID=8YFLogxK

M3 - Article

VL - 76

SP - 442

EP - 446

JO - American Journal of Clinical Nutrition

JF - American Journal of Clinical Nutrition

SN - 0002-9165

IS - 2

ER -