Surviving menopause - Calcium, Vitamin D and Osteoporosis

As menopause approaches, many women begin to worry about osteoporosis and how to prevent it. This is something to be concerned about because the drop in estrogen production which occur after menopause causes an increase in bone loss leading to fragile bones.

Factors which increase the risk of developing osteoporosis include:

1. low bone density (thickness of your bones) at the time of menopause


2. smoking


3. premature menopause


4. removal of the ovaries and uterus


5. drugs (e.g. some asthma medications)

After menopause, bone loss is almost inevitable, so at this point, you're trying to reduce the rate at which it is lost, and if possible reverse the loss.

The WHI (Women's Health Initiative) trials on the effects of hormone replacement therapy also included a trial on the effects of Calcium and Vitamin D supplementation on

1. the risks of suffering hip fractures and other fractures which are strongly associated with osteoporosis,


2. bone density and


3. the risk of getting colorectal cancer.

The 36,252 women who chose to take part in the Calcium/Vitamin D (CaD) trial were randomly assigned to two groups:

1. one group taking a pill containing 500mg of Calcium and 200IU (IU = international units) of Vitamin D twice a day (a total of 1000mg of Calcium and 400IU of Vitamin D daily)


2. the other group receiving an inactive placebo.

The participants were followed for an average of 7 years.

Findings of the Calcium and Vitamin D study

The study had the following findings for the CaD group compared to the placebo group:

1. overall, women taking CaD had 12% fewer hip fractures


2. they had slightly fewer fractures overall but the difference was not significant


3. women who took their pills regularly had 29% fewer fractures than the placebo group


4. women 60 years and over had a 21% decreased risk of hip fracture compared to women over 60 in the placebo group


5. women on CaD had slightly increased bone density


6. they also 17% more kidney stones


7. there was no difference in the occurrence of colorectal cancer between the two groups

It is important to note that many of the women enrolled in the CaD trial already had a lower risk of developing hip fractures than women in the general population because:

1. most were on hormone replacement therapy which reduces the risk of developing osteoporosis


2. many already had a high personal intake of Calcium and Vitamin D


3. most had higher than average weight which also tends to reduce risk

These observations may explain the fact that there wasn't much difference overall between the two groups. It is possible that differences may be greater in women who are not on hormone replacement therapy.

What does this mean for women worried about osteoporosis

1. Women over 50 should take a total of 1000 - 1200mg of Calcium and 400 - 600IU of Vitamin D a day.


2. Calcium and vitamin D are more effective when they are taken regularly.


3. Lifestyle changes that can help include :
   
   • eating a low fat, high fibre diet
   
   
   • carrying out weight-bearing exercise (e.g. walking and climbing stairs). The benefits of exercise aren't limited to helping to reduce bone loss. Women who exercise have better posture and balance and are less likely to fall in the first place and so tend to have fewer fractures.