From the Guidelines
The best calcium supplement for bone support is calcium citrate, taken at a dose of 500-600mg twice daily for a total of 1000-1200mg per day. This recommendation is based on the most recent and highest quality study available, which suggests that calcium citrate is more easily absorbed than other forms, especially for older adults or those with reduced stomach acid 1.
For optimal absorption, it is recommended to take calcium supplements with food and split the doses throughout the day since the body can only absorb about 500mg at once. Pairing calcium with vitamin D3 (1000-2000 IU daily) is also crucial as it significantly enhances calcium absorption and utilization for bone health 2, 1. Additionally, magnesium (300-400mg daily) is beneficial as it works synergistically with calcium.
While supplements are helpful, it is essential to prioritize calcium-rich foods like dairy products, fortified plant milks, leafy greens, and canned fish with bones. These dietary sources provide calcium in its most bioavailable form along with other bone-supporting nutrients. Regular weight-bearing exercise is equally important for maintaining bone density alongside calcium supplementation. The daily calcium intake recommendations vary by age, with at least 1000 mg per day recommended for individuals under 50 years of age and at least 1200 mg per day for those older than 50 years 1.
Key points to consider:
- Calcium citrate is the preferred form of calcium supplement due to its ease of absorption
- Vitamin D3 and magnesium supplements are also essential for bone health
- Dietary sources of calcium should be prioritized
- Regular weight-bearing exercise is crucial for maintaining bone density
- Daily calcium intake recommendations vary by age, with higher amounts recommended for older adults 2, 1
From the Research
Forms of Calcium Supplements
- Calcium carbonate and calcium citrate are the most common forms of calcium supplements 3
- Calcium carbonate is the most cost-effective form, but should be taken with a meal to ensure optimal absorption 3
- Calcium citrate can be taken without food and is the supplement of choice for individuals with achlorhydria or who are taking histamine-2 blockers or protein-pump inhibitors 3
- Calcium lactate and calcium gluconate are less concentrated forms of calcium and are not practical oral supplements 3
- Hydroxyapatite is not recommended due to limited research on its effectiveness as a source of calcium 3
Effectiveness of Calcium Supplements for Bone Health
- Calcium supplementation has been found to be beneficial for bone health in children, young adults, and menopausal women 3
- Calcium citrate decreased markers of bone resorption significantly more than calcium carbonate in postmenopausal women 4
- Calcium supplementation can help increase bone mineral density and decrease fractures 5, 4
Potential Adverse Effects of Calcium Supplements
- Gastrointestinal complaints are a potential adverse effect of calcium supplementation 3
- Renal calculi (kidney stones) are not typically associated with calcium supplementation, with some studies finding no significant increase in risk 3, 6
- High calcium intakes (>1500 mg/d) may be associated with an increased risk of advanced and fatal prostate cancer 3
- Calcium supplementation has been linked to both increased and decreased cardiovascular disease risk, creating uncertainty 7