Osteoporosis

Background. Osteoporosis, falls and related fragility fractures are a significant health problem.  Currently it is estimated 30-50% women and 15-30% of men will suffer an osteoporotic fracture in their lifetime.

Vitamin D.

Vitamin D is present in only a few foods. Because so very few foods contain vitamin D for the 90% of vitamin D requirements most people comes from casual exposure to sunlight. With our indoor lifestyles, it is the reason why vitamin D deficiency has become epidemic for all age groups in the US and Europe, causing metabolic bone disease in children are adults but also increasing the risk many common chronic diseases, including chronic pain. The adult’s vitamin D deficiency has effects on the skeleton. People who are vitamin D deficient are at risk of reduced bone mineral density which can precipitate or exacerbate osteoporosis. The impact of supplemental vitamin D on fracture risks been examined mainly men and women aged 65 and older. A recent study revealed that vitamin D doses in the range of more than 10 to 20 mg per day reduce the risk of non-vertebral and hip fractures by 20% whereas doses up to 10 mg today had no effect

Clearly in our community there is concern about skin cancer from sunlight. The most serious for these melanoma. However on the basis of our understanding of the efficiency of sun exposure producing vitamin D in skin it is reasonable to allow some sun exposure without some protection for productions of adequate amounts of the vitamin D.

Sun Exposure Recommendations from Osteoporosis Australia

Factors that affect the production of vitamin D by the skin.

Age. A person 70 years of age exposed the same amount of sunlight has a 20-year-old makes approximately 25% of vitamin D that the 20-year-old person can make.

Darker skin requires longer exposure of sun to make the same amount of vitamin D compared to light-skin.

Sunscreens also work to reduce the production of vitamin D and a sunscreen and sun protection factor of eight reduced the capacity of the skin to produce vitamin D by over 95%.

Time-of-day, season and latitude also dramatically influence vitamin D production from the skin. Above the 37° latitude very little if any vitamin D is produced in the skin during winter. Similarly early in the morning and late in the evening very little vitamin D is produced by the skin.

Obesity. Vitamin D is also fat-soluble. Therefore for obese individuals affected be an irreversible sink for vitamin D increase the risk of vitamin D deficiency.

Prevalence and detection of vitamin D deficiency The only way to determine whether a person is vitamin D sufficient, efficient or intoxicated is to measure the circulating concentrations which is produced in the liver. This can be done by a blood test.

Exercise. Although exercises widely recommended as one of the key preventative strategies to reduce risk of osteoporotic fractures its effects on bone were for some time controversial because of its potential for improving whole bone strength had not been properly assessed.

Over the last two decades there been a number of well-designed clinical trials. A study on middle-aged and older men aged between 50 and 79 years showed that a combination high-intensity progressive resistance training with a diverse range of moderate impact weight-bearing exercises before three times a week resulted in a 2% net gain in femur bone mineral density. This is small but considered significant in reducing fracture risk. One study looked at identical twins who had divergent exercise regimes, and found that those who engaged in regular exercise had 18% greater bone mass at the tibia. 

Type and amount of Exercise. The data indicates that the most successful programs are performed 3-5 times per week preferably on a daily basis for 10 to 45 minutes per session. 

The general consensus for middle-aged and older adults is that low to moderate impact weight-bearing exercise in combination with progressive resistance and/or agility training is most effective for improving hip and spine bone mineral density.

Exercise has benefits beyond bone strength and the improvements in muscle strength and balance combined with increases in bone mineral density have been shown to reduce fracture incidence by up to 50%.

 

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Dawson-Hughes et al. IOF position statement: vitamin D recommendations for older adults

Holick, Mi. Sunlight and vitamin D for bone health and prevention of autoimmune diseases, cancers, and cardiovascular disease

Kemmler W, et al. Exercise effects on none mineral density, falls, coronary risk factors and health care costs in older women: the randomized controlled senior fitness and prevention study. Arch intern med 2010

Nikander et al BMC Medicine 2012, 8:47 Targeted exercise against osteoporosis: a systematic review and meta-analysis for optimising bone strength throughout life

Web Address. Osteoporosis Australia Resources. 

https://www.osteoporosis.org.au/resources?cta=Osteoporosis%20information