From the Guidelines
Dietary calcium restriction is not recommended for most people, as it can lead to decreased bone mineral density and increased risk of osteoporosis over time. When calcium intake is limited, the body compensates by pulling calcium from bones to maintain normal blood calcium levels, weakening the skeletal structure. This restriction may temporarily lower urinary calcium excretion, which might be beneficial in specific conditions like certain types of kidney stones (calcium oxalate or calcium phosphate stones) 1. However, long-term calcium restriction is generally not recommended, as it can have negative effects on bone health. The typical adult requires 1000-1200 mg of calcium daily for optimal bone health, and this can be achieved through a balanced diet that includes dairy products, leafy greens, and fortified foods 1.
Instead of restricting calcium, a balanced approach that includes:
- Adequate calcium intake
- Vitamin D supplementation to enhance calcium absorption
- Regular weight-bearing exercise
- Limiting sodium and animal protein consumption is more effective for overall health. This approach can help maintain strong bones, reduce the risk of osteoporosis, and minimize the risk of kidney stones. Calcium restriction should only be implemented under medical supervision for specific conditions where the benefits outweigh the risks of bone demineralization, such as in patients with certain types of kidney disease or kidney stones 1.
In patients with chronic kidney disease (CKD), the recommended daily calcium intake is 2.0 g/day, which can be achieved through a combination of dietary calcium and supplements 1. However, it is essential to monitor urinary calcium excretion and adjust the calcium intake accordingly to avoid hypercalcemia. In patients with kidney stones, a diet with normal calcium content (1200 mg/day) and low amounts of animal protein and salt can help reduce the risk of stone recurrence 1.
In summary, a balanced approach to calcium intake, rather than restriction, is recommended for most people, and medical supervision is necessary for specific conditions where calcium restriction may be beneficial.
From the Research
Dietary Calcium Restriction
- Dietary calcium restriction may not have a significant impact on bone density or the rate of bone loss in healthy older women, as shown in the re-analysis of data from the Auckland Calcium Study 2.
- The relationship between calcium intake and bone density is still a topic of controversy, with most studies showing little evidence of a relationship between the two 2.
- Inadequate dietary calcium in early life can impair bone development, while in later years it can accelerate bone loss and contribute to osteoporosis 3.
- Calcium supplementation has been shown to reduce the rate of loss of bone mineral density in post-menopausal women and older men, but the extent to which this outcome reduces fracture risk is still unclear 3.
Bone Health and Osteoporosis
- Osteoporosis is a systemic skeletal disorder characterized by bone loss, which leads to impaired bone strength and an increased risk of fractures 4.
- Bisphosphonates are widely used for the prevention and treatment of osteoporosis, but their use remains a clinical challenge due to considerations such as patient selection, pretreatment evaluation, and potential adverse effects 4.
- Calcium supplementation alone or in combination with other treatments for osteoporosis does not significantly increase the risk of nephrolithiasis or renal colic 5.
Calcium Intake and Bone Mineral Density
- A systematic review of longitudinal cohort studies found that calcium intake is not an important determinant of bone loss, particularly among women over 60 years old 6.
- Most studies found no association between calcium intake and change in bone mineral density in women (71%) or men (71%) 6.
- High rates of hormone treatment or osteoporosis therapy use were associated with a positive association between calcium intake and change in bone mineral density, but this may be due to confounding as a result of co-administration of calcium supplements with these medications 6.