Osteoporosis is a common bone disease (Norman & Henry, 2012), typically manifesting itself later in life. Certain diets and lifestyles during the first 20 years of life, however, can greatly increase its risk (Anderson, 2012).
Osteoporosis is a progressive bone disease defined by a decrease in bone mass and density (Biesalski, Grimm & Nowitzki-Grimm, 2015). Reduced bone mineral content or bone mineral density and micro-architectural defects of the organic matrix as well as of the mineral phases result in increased skeletal fragility and susceptibility to fractures (Anderson, 2012). Osteoporosis is measured by using a dual-energy X-ray absorptiometry, by means of which architectural defects are rated by histomorphometry and physical tests of bone strength (Biesalski et al., 2015). The World Health Organization (WHO) defines osteoporosis with a t-score 2.5 SD and above. The pre-stage of osteoporosis, called osteopenia, has a t-score between 1-2.5 SD. In 2012, some 300’000 persons were diagnosed with osteoporosis in Switzerland (Federal Office of Public Health, 2012). In 2014, 54 million people were diagnosed with osteoporosis in the USA resulting in high public health care costs (National Osteoporosis Foundation, 2014). Women are at higher risk for osteoporosis than men (Anderson, 2012). Patients with decreased bone density are more prone to hip and spinal fractures, but interestingly not all osteoporosis patients will suffer fractures despite their low bone density values. Accordingly, there must be other factors that reduce the risk of fractures in osteoporosis patients.
It is well established that major risk factors are age (>75 years), gender (female>male), race (Caucasians, Asians), body weight, hormonal balance and behavioural lifestyle (Anderson, 2012; Nordin et al., 2004). Other risk factors are the way a person’s bone architecture and mass develops before he or she reaches adulthood. These include genetics, diet and physical activity (Goulding et al., 2004; Weaver & Heaney, 2008) during childhood and adolescence. This report describes how a person’s life style and diet can increase the risk of osteoporosis.
Starting with diet, data suggest that calcium, phosphorus, vitamin D, protein, vitamin K and A as well as magnesium and fluoride have a high impact on bone strength (Kerstetter et al., 2003). It should be noted however, that excessive or deficient intake can also cause health problems (Anderson, 2012; Knapen et al., 2007). Too little macronutrients in the diet and increased bone loss increase the risk of bone fragility and fracture (Anderson, 2012). Calcium intake, whether in form of diet or by means of supplements, is never fully absorbed by the body. To compensate for the loss of macronutrients through urine, sweat and faeces, it is crucial that patients take higher than recommended doses of calcium (Bauer, 2013).
Calcium is the most abundant mineral in the body, with around 98% in the skeleton (Bauer, 2013). An increase in calcium lowers the parathyroid hormone (PTH) concentration within the normal reference range (McKane et al., 1996), which in turn has a beneficial effect in reducing the risk of fracture (Anderson, 2012). Caution is needed when taking high amounts of phosphorus, which has a lowering effect on PTH. Preferred sources for calcium are diary products (milk, cheese, yogurt), green leafy vegetables (broccoli, fennel, kale), fish (sardines, pink salmon), herbs (basil, parsley) and nuts (hazelnut, almonds, sesame) (Biesalski et al., 2015; U.S. Department of Agriculture, 2013). Unabsorbed calcium is a risk factor, which can lead to kidney stones (Worcester & Coe, 2010) and colon cancer as well as an increased risk of hypertension, obesity, premenstrual syndrome, polycystic ovary syndrome and hyperparathyroidism (Weaver, 2012). Recommended levels of calcium intake for adults of all ages is between 500 to 1300mg/day (Biesalski et al., 2015). The Institute of Medicine (2011) recommends a dietary intake of calcium of 1000mg/day for women 19 to 50 years of age and men 19 to 70 years of age. The recommended dietary intake for women over 50 and men over 70 is 1200mg/day. Calcium intake over 2500mg/day should be avoided due to increased risk of cardiovascular disease (CVD) (Bolland et al., 2010). Actual calcium intake by adolescents and the elderly is much lower than recommended (Bailey, et al., 2010; Biesalski et al., 2015; Looker, 2006), partially due to inadequate diet. Furthermore among the elderly, slow digestion results in lower absorption of calcium (Anderson, 2012). If the amount of calcium can’t be ingested through nutrition, calcium carbonate or calcium citrate supplements are required and should be taken with meals (ca carbonate) for improved absorption and decreased risk of kidney stones (Weaver, 2012). However it has also to be considered that supplementation can lead to supersaturation of urinary calcium oxalate and phosphate concentration, which is the driving force in the formation of kidney stones (Worcester & Coe, 2010). Decreased hypercalcuria can be achieved by raising fluid intake (>2l/day) and lowering diet intake of protein (0.8/1g per kg BW), sodium (2300mg/day) and oxalate (Borghi et al., 2002). Recommended dose for vitamin D is 600 IU for persons 1 to 70 years of age, and 800 IU for babies and persons older than 70 years of age (Institute of Medicine, 2011). Chronic vitamin D deficiency in the elderly can result in an imbalance of bone repair and exacerbate bone loss (Norman & Henry, 2012), which is associated with hypertension, obesity, glucose intolerance and the metabolic syndrome (Michos & Blumenthal, 2007). It should also be noted, that calcium supplements can lead to constipation, bloating (especially calcium carbonate) and, less frequently, nephrolithiasis and CVD (Bauer, 2013). Increased CVD due to calcium supplement intake has not been confirmed (Holligan et al., 2012).
Vitamin D is important for the maintenance of calcium and phosphate homeostasis, as well as the immune system, brain, heart and CV system (Norman & Henry, 2012). Data also suggests that combined intake of calcium and vitamin D has a modest protective effect on fractures (Chung et al., 2009; Norman & Henry, 2012; Tang et al., 2012), although earlier studies by Rosen (2011) and Hunt and Johnson (2007) do not corroborate these findings. Daily exposure to sunlight provides sufficient levels of vitamin D in most humans. In case of vitamin D insufficiency regular intake of cod liver or fish with high fat content is recommended (Biesalsky et al., 2015). In addition to nutritional factors, regular physical activity with high resistant impact to strengthen the bones like jogging is also thought to lower the risk of osteoporosis (Biesalski et al., 2015). Hormone deficiency (estrogens and androgens), mostly due to menopause, is also linked to higher risk of osteoporosis (Bauer, 2013). The impact of estrogens in bone mineralization on postmenopausal osteoporosis, however, has been overestimated (Biesalski et al. 2015). Bone density in obese persons is believed to decrease the risk of osteoporosis due to greater conversion of steroid hormones into estrogens (Anderson, 2012). At last, intake of drugs, diseases like anorexia nervosa, renal failure etc. as well as smoking can interfere with the necessary calcium absorption, which in turn can lead to osteoporosis (Biesalski et al., 2015).
In summary: The recommended daily calcium intake of a person under 50 years is 1000mg, over is 1200mg. I advise people to increase their current dietary calcium intake if it is lower than recommended in form of calcium-rich vegetables, fruits, nuts and diary products and discontinue the calcium supplements. If this is not feasible, I would supplement the calcium intake by calcium citrate. While the intake of calcium supplements potentially increases the risk of nephrolithiasis and CVD, these findings have not been proven. To avoid kidney stones, you should try to increase your fluid intake to at least 2l/day. I also highly recommend to increase your physical activity by regularly walking outdoors or jumping on the trampoline in order to strengthen your bones and increase vitamin D absorption. You should be careful about the sun exposure though, because of increased risk of skin cancer and non-lethal skin damage. To ensure adequate intake of vitamin D, I would recommend doing a blood test measuring your vitamin D levels and determining how much vitamin D supplements are required. Finally, I urge you to avoid smoking, alcohol and the intake of high sugar foods and follow a healthy, well-balanced macronutrient diet.
If you are interested in supplements, check this out.
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