Recommended Daily Calcium Intake for Adults
The recommended daily intake of calcium for adults is 1000 mg/day for women aged 19-50 years and men aged 19-70 years, and 1200 mg/day for women over 50 years and men over 70 years. 1, 2
Age and Sex-Specific Recommendations
- Adults aged 19-50 years (both men and women) require 1000 mg of calcium per day 1, 2
- Men aged 51-70 years require 1000 mg of calcium per day 1, 2
- Women over 50 years require 1200 mg of calcium per day 1, 2
- Men over 70 years require 1200 mg of calcium per day 1, 2
- Pregnant or lactating women should follow the same recommendations as their age group (1000 mg/day) 2
Safety Limits
- The upper intake level for calcium is 2500 mg/day for adults aged 19-50 years 1, 2
- For adults over 50 years, the upper intake level is reduced to 2000 mg/day 1, 2
- Calcium intake above these levels should be avoided due to potential adverse effects 1
Sources of Calcium
- Dietary sources of calcium are preferred over supplements whenever possible 1
- Dairy products provide approximately 70% of dietary calcium for most adults 1
- Non-dairy sources include green leafy vegetables, nuts, soya beans, and calcium-fortified foods 1
- When estimating dietary calcium intake, clinicians can assume that most adults consume about 300 mg of calcium per day from non-dairy sources 1
Calcium Supplements
- Calcium supplements should be considered when dietary intake is inadequate 1
- For optimal absorption, calcium supplements should be taken with meals 1
- Doses greater than 500 mg should be divided throughout the day to improve absorption 2
- Calcium carbonate contains 40% elemental calcium and is more economical 2
- Calcium citrate contains 21% elemental calcium and has better absorption without food 2
Potential Risks of Calcium Supplementation
- Calcium supplements may cause side effects such as constipation and bloating 1
- There is an increased risk of kidney stones with calcium supplements, but not with dietary calcium 1, 2
- Some studies have raised concerns about a possible increased cardiovascular risk with calcium supplements, though evidence remains inconsistent and inconclusive 1, 2
Special Considerations
- Adequate vitamin D is essential for optimal calcium absorption 1
- In cases of glucocorticoid-induced osteoporosis, calcium and vitamin D supplementation should be optimized alongside other treatments 1
- For older adults with low dietary calcium intake, a daily calcium supplement of 500 mg may be needed 1
- Calcium requirements may be higher (1500 mg/day) in specific populations such as postmenopausal women not on estrogen therapy 3, 4
Following these recommendations for calcium intake, along with appropriate vitamin D levels and lifestyle modifications, helps maintain optimal bone health and reduce fracture risk throughout adulthood.