Calcium and vitamin D are two of the most important nutrients for bone health. Unfortunately, as compared to younger people, seniors are especially vulnerable to calcium and vitamin D deficiency – largely because the body changes with advancing age.
With ageing there is…
- a decrease in dietary calcium intake, usually as a result of decreased overall calorie intake. For example, seniors may have poor appetite in general or illnesses that decrease appetite. There are social and economic factors too that may contribute to malnutrition in seniors.
- a decrease in the intestinal absorption of calcium (especially if vitamin D status is low) as well as a decrease in the capacity of the intestinal cells to adapt to a low calcium intake as they would in healthy younger people.
- less frequent exposure to sunlight. As vitamin D is produced in the body when skin is exposed to sunlight, less sun exposure may lead to poor vitamin D status. This is a special problem in elderly who are housebound, or institutionalized, or have reduced mobility.
- a decrease in the capacity of the skin to synthesize vitamin D. In the elderly the skin produces 4-times less vitamin D when exposed to the sun, as compared to younger people.
- a decrease in the efficiency with which the kidneys can retain calcium, leading to increased calcium loss in the urine.
- a decrease in the capacity of the kidneys to convert vitamin D into its most active form (1,25-dihydroxyvitamin D).
For all these reasons, calcium and vitamin D intake recommendations are higher in seniors.
The IOM recommended daily allowance for calcium in seniors aged 70 and over is 1,200 mg per day. While this is achievable through the diet, some seniors (especially those with reduced appetite) may need a supplement to meet recommended intake.
Given the indoor-lifestyle of most seniors, little sunshine in winter months, and the various physiological factors related to ageing, it is very common for seniors to have poor vitamin D status. IOF therefore recommends that seniors aged 60 years and over take a supplement at a dose of 800 to 1000 IU/day. Vitamin D supplementation at these levels has been shown to reduce the risk of falls and fractures by about 20%.
This article appeared in our monthly Love Your Bones newsletter - sent free to all IOF members.
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