Mineral Absorption—Carbohydrate That Enhances Calcium Uptake Which dietary carbohydrate is most effective at promoting intestinal absorption of calcium, particularly in infants and young children?

Introduction / Context:
Diet composition modulates mineral absorption. Calcium uptake in the small intestine can be influenced by the accompanying carbohydrate, luminal pH, and vitamin D status. Lactose has a well-documented enhancing effect on calcium absorption, especially in early life when milk is a staple food.

Given Data / Assumptions:

• Question asks specifically which carbohydrate promotes calcium absorption.
• Physiological context includes milk-based diets in infants.
• Normal vitamin D and parathyroid hormone regulation are assumed.

Concept / Approach:
Lactose may increase calcium solubility and stimulate passive paracellular transport by retaining water and creating favorable luminal conditions. It can also influence microbiota fermentation products that lower pH and improve mineral ionization. Other disaccharides do not consistently show the same effect in vivo.

Step-by-Step Solution:

Verification / Alternative check:
Balance studies demonstrate higher fractional calcium absorption with lactose-containing formulas compared with lactose-free counterparts in infants.

Why Other Options Are Wrong:

• Maltose, sucrose, xylose, and fructose do not reliably enhance calcium absorption to the same extent; some may be neutral or context-dependent.

Common Pitfalls:
Extrapolating benefits to lactose-intolerant adults; intolerance necessitates alternative strategies (e.g., lactase-treated products, calcium-citrate, vitamin D optimization).

Final Answer:
Lactose