What is the appropriate oral calcium supplementation dose per kilogram for a healthy 5‑year‑old child?

Oral Calcium Supplementation Dose for a Healthy 5-Year-Old Child

For a healthy 5-year-old child, the appropriate oral calcium supplementation dose is 10-16 mg/kg/day of elemental calcium, with total daily intake (diet plus supplements) targeted at 800-1,200 mg/day (100-200% of the age-specific DRI). 1, 2

Weight-Based Dosing Framework

• The standard weight-based dose for children ages 1-18 years is 10-16 mg/kg/day of elemental calcium when supplementation is needed beyond dietary intake 2
• For a typical 5-year-old weighing approximately 18-20 kg, this translates to 180-320 mg/day of elemental calcium from supplements 2
• The total daily calcium intake (food plus supplements) should reach 100-200% of the DRI for age, which is 800 mg/day for children ages 4-8 years 1

Calculating Supplementation Needs

The actual supplement dose must account for dietary calcium intake:

• First, assess the child's dietary calcium intake from milk, dairy products, fortified foods, and other sources 3
• If dietary intake is 400 mg/day, supplementation of 400-800 mg/day would be appropriate to reach the target of 800-1,600 mg/day total 1
• The lower end (100% DRI = 800 mg/day total) is appropriate for children with normal dietary intake, while the upper end (200% DRI = 1,600 mg/day total) represents the maximum safe limit 1

Optimal Formulation and Administration

Calcium carbonate is the most cost-effective and practical supplement for pediatric use:

• Calcium carbonate contains 40% elemental calcium by weight, making it the most concentrated oral form 3, 4
• Administer calcium carbonate with meals because gastric acid is required for dissolution and optimal absorption 4, 5
• Other calcium salts contain less elemental calcium: calcium acetate (25%), calcium lactate (13%), and calcium gluconate (9%) 3

Dosing Strategy to Maximize Absorption

• Do not exceed 500 mg of elemental calcium per dose to maximize absorption efficiency 4
• For higher total daily doses, divide into 2-3 doses throughout the day with meals 4
• Each 1,250 mg calcium carbonate tablet provides approximately 500 mg elemental calcium 4

Essential Cofactors

Vitamin D is essential for optimal calcium absorption:

• Children ages 1-18 years require 600 IU/day of vitamin D 1
• Without adequate vitamin D, calcium absorption is significantly impaired regardless of intake 6

Critical Safety Limits

The upper safe limit for total calcium intake in children ages 1-8 years is 2,500 mg/day:

• Exceeding this limit increases the risk of adverse effects including constipation, hypercalcemia, and potential interference with absorption of other minerals 1, 7
• This upper limit represents approximately 200% of the DRI and should not be exceeded 1

Common Pitfalls to Avoid

• Never use calcium chloride as an oral supplement as it can cause metabolic acidosis 3, 1
• Do not administer calcium carbonate on an empty stomach, as bioavailability is markedly reduced 4
• Avoid calcium citrate in children with chronic kidney disease, as it enhances aluminum absorption 1
• Monitor for constipation and abdominal bloating, the most common side effects of calcium carbonate 4

Monitoring Adverse Effects

• The most common side effects are constipation and abdominal bloating; regular monitoring is advised 4
• If gastrointestinal symptoms occur, consider reducing individual dose size and increasing frequency, or switching to calcium citrate (which can be taken without food) 5