Osteoporosis

Thinning of the bones is a natural consequence of ageing but the rate at which it occurs and the risk of developing a fracture are determined by many lifestyle as well as nutritional factors.  According to the National Osteoporosis Society www.nos.org.uk there are 230,000 osteoporotic fractures per year in the UK and osteoporosis costs the NHS about £1.7 billion per year.
A healthy diet with adequate provision of calcium, vitamin D, (most of which comes from sun exposure), vitamin K and other nutrients helps to reduce the risk significantly.  However it is now clear that an excess of vitamin A is a major risk factor for osteoporosis.

Vitamin A

An excessive intake of the retinol form of vitamin A from diet or supplements, or a high blood level of retinol are risk factors for reduced bone mass and increased fracture risk.
The Scientific Advisory Committee on Nutrition produced a report, Review of Dietary Advice on Vitamin A in September 2005 advising on this issue.  http://www.sacn.gov.uk/pdfs/sacn_vita_report.pdf

Supplements containing retinol, which includes most multivitamins and cod liver oil should not be taken by those with osteoporosis or who are at high risk of developing it unless they are known to be deficient.
Particular care needs to be taken by:

• those who consume liver or liver products e.g. pâté, regularly once per week or more often
• those with a high plasma retinol > 2.5 umol/l;
  20% of adults aged 50-64 years, 25% of the free-living elderly 65 years and older and
  18% of the institutionalised elderly 65 years and older
• those with a condition that predisposes to osteoporosis and retinol excess including renal impairment, liver disease or alcohol excess 

All of the above should seek medical advice before taking any vitamin supplement containing retinol.
Supplements of beta-carotene have not shown such an association and consumption of fruits and vegetables, which are rich in this form of vitamin A, is usually associated with a reduced risk of osteoporosis and fracture.

See also http://www.nof.org/cmexam/Issue2OTC/OTCOnlineCME.pdf  Referenced advice from the US based National Osteoporosis Foundation

Calcium and Vitamin D

These simple and generally safe supplements are of proven benefit in the treatment and prevention of osteoporosis in people who are typically aged 70 years and over.  Vitamin D Guidance Level is set at 25 ug per day which means that both a multivitamin and a calcium and vitamin D preparation can be taken without this level being exceeded.  The Safe Upper Level for calcium is 1.5 g per day and as most supplements used for osteoporosis provide 2 x 500 mg tablets per day and dietary intakes in the UK average 700 mg per day then this level may be slightly exceeded.  There have been a few reports suggesting that this level of total intakes >1500 mg per day may be associated with an increase in the risk of prostate cancer in men and vascular disease in elderly women.  In those who are considered to be at increased liver risk of these conditions it may be prudent to limit supplemental intake to 500 mg per day if the risk of osteoporosis is only moderate.  However in those aged over 80 years vitamin D intake should probably remain at 10 ug per day

For further simple information see National Osteoporosis Society www.nos.org.uk