The Working Group of the Australian and
New Zealand Bone and Mineral Society (ANZBMS) and Osteoporosis Australia
(OA) recently recommended the use of combination supplemental calcium
and Vitamin D to improve bone mineral density for elderly men and women.
In a position statement from the advisory group found in the March 16
edition of the Medical Journal of Australia, the following was
highlighted about a recent review of the current research on calcium and
vitamin D:
Key Recommendations:
- Randomised controlled trials show that, in people with a
baseline calcium intake of 500-900 mg/day, increasing the intake by a
further 500-1000 mg/day has a beneficial effect on bone mineral density
(BMD).
- The effect of calcium supplementation on bone health is modest,
as shown by increases in BMD and reductions in excessive bone turnover.
The relative risk reduction for osteoporotic fracture is likely to be no
more than 10-20%. There is little evidence with fracture endpoint in
men.
- Although inadequate calcium intake is likely to be deleterious
to bone, calcium intake significantly above the recommended level is
unlikely to achieve additional benefit for bone health. Thus, strategies
to increase calcium intake should be focused on people whose calcium
intake is lowest.
The first recommendation is the most
important for practice, particularly in patients susceptible to low
calcium such as the elderly and pregnant and breastfeeding women.
Maintenance of bone density is critical for preventing diseases of the
bone such as osteoporosis, particularly in those people at higher risk.
Other key findings from the report
are:
- Calcium deficiency reduces bone mass by inducing the breakdown
of bone and release of calcium to maintain calcium levels in
extracellular fluid
- Vitamin D and calcium interact: a low calcium intake may cause a
relative vitamin D deficiency and inadequate vitamin D exacerbates a
calcium deficiency by reducing absorption of dietary calcium
- Adequate vitamin D is essential for absorption of dietary
calcium and for the maintenance of bone mass
Pregnancy and Breastfeeding
- In pregnant women, calcium is mobilised from bone for foetal
growth needs
- In lactating women, calcium is mobilised from bone for
breastmilk production and bone is rebuilt after weaning
Elderly
- In adults, bone mass remains relatively stable up to age 50
years for men and up to menopause for women
- Post-menopause, women lose bone mass at a rate of about 2-3% a
year for the first five years and about 1 per cent a year from then on
- Post-menopause, calcium absorption decreases and urinary losses
increase.
- It is difficult for many older adults to achieve the recommended
dietary intake of calcium from food.
- Calcium treatment reduces bone loss in men and women by 50-60%
These are the latest recommendations for
the maintenance of bone density and bone health, from the Working Group
of Australia and New Zealand Bone and Mineral Society (ANZBMS) and
Osteoporosis Australia (OA), which emphasize the importance of calcium
and vitamin D in nutrition.
The original report can be found in the
Medical Journal of Australia (MJA 2009; 190 (6): pp316-320)
