If we are to remain as active as possible as we move through the different stages of our lives, optimising the health of our musculoskeletal system is important. As we age, the focus of public health initiatives, including disease prevention, shift. Whereas the incidence of disorders such as osteoporosis and osteoarthritis tend to increase as we get older, problems such as lower back pain are common in the working age population. In recent years, in the UK, we have seen an increasing number of cases of rickets in children, which is also a concerning trend.
Whilst for the individual, the consequences of living with pain and reduced function can negatively impact on their quality of life, musculoskeletal disorders are a drain on a country’s healthcare resources and economic productivity of the workforce. To put this into context, each year in the UK 20% of people seek medical advice from their doctor about a musculoskeletal problem with an estimated annual cost to the NHS of £5 billion. Many musculoskeletal disorders can be prevented by following a healthy lifestyle, along with avoidance of being sedentary and not smoking, diet is one aspect of our lives that we can modify, to optimise musculoskeletal health.
In addition, it is important to acknowledge the consequences that the rise in obesity is having on musculoskeletal health across the lifespan. Throughout this course, you will have already learnt about the importance of vitamin D in preventing rickets in children and osteomalacia in adults. About how foods containing calcium and phosphorus are required in our diets for a strong musculoskeletal system, and how protein rich foods that contain the essential amino acids, optimise the health and function of our muscles. In addition to understanding how these nutrients work, it’s also important to consider how much of each nutrient is required and how this need changes as we age.
The reference nutrient intake, or RNI, is the figure set by the UK Department of Health, as the recommended amount of a nutrient that is sufficient to meet the dietary needs of 97.5% of the population. If we take calcium as an example, we can see that as we age the RNI for calcium drops from 525 milligrams per day at birth, to 350 milligrams per day at one year of age. How much calcium we then need steadily rises during childhood, to a maximum between 11 and 18 years of age of 1,000 milligrams per day for males, and 800 milligrams per day for females.
These changes in requirements can be explained by the increased need for calcium during periods of rapid growth and as bone mass increases from birth to adolescence. Throughout adulthood, for most people, our requirements remain at 700 milligrams per day. There are some exceptions to this including women who are breastfeeding, who should aim to consume an additional 550 milligrams per day, individuals with conditions that can impair calcium absorption, such as coeliac disease and inflammatory bowel disease, where increased requirements of between 1,000 and 1,500 milligrams per day are recommended. And people diagnosed with osteoporosis, who should aim for 1,000 milligrams per day.
More recently, our understanding of how calcium metabolism changes during the menopause, have also led to calcium requirements for post-menopausal women, being set at higher level of 1,200 milligrams per day. As with many micronutrients, excessive intakes can be detrimental for health. For calcium, the health risks associated with high intakes, are not fully understood. As a result, no safe upper intake level has been set in the UK. It is important to note, that due to differing use and interpretation of the research evidence base, governmental nutrient recommendations differ. For example, in North America, the recommended dietary allowance for calcium for an adult 19 to 50 years, is 1,000 milligrams per day whilst in the UK it is 700 milligrams per day.
Depending on where you are studying or working these differences may need to be considered.