This piece was written by one of our contributors; consultant dietitian (and resident dietitian for The Food Medic) – Maeve Hanan
More than 3 million people in the UK have osteoporosis, which is a loss of bone mass (1). Osteoporosis increases the risk of fractures and is most likely to occur in post-menopausal women, due to the impact of low oestrogen levels on the bones.
Osteopenia is the stage before osteoporosis, where bone density is low but not low enough to be classed as osteoporosis. Both osteoporosis and osteopenia can be diagnosed using a DEXA scan; a T-score of -1 to -2.5 SD indicates osteopenia, and below -2.5 indicates osteoporosis. It is very important to address osteopenia, as this can help to prevent the development of osteoporosis.
This article will explore the crucial role that nutrition plays in keeping our bones healthy.
Protein
Roughly 50% of our bones are made up of protein, so this is a vital nutrient in terms of bone health (2).
The recommended intake of protein for adults is 0.75g per kg body weight per day, and this increases to 1.2 – 2g per kg per day for athletes (3). For best results it is important to spread protein intake across the day, as our body can only use about 0.25 – 0.4g per kg body weight of protein per meal (3).
Most people in the UK consume enough protein, but at higher risk of protein deficiency include: older adults, vegetarians, vegans and athletes.
Good sources of protein include:
- Meat ?
- Poultry ?
- Seafood ?
- Dairy ?
- Eggs ?
- Beans and pulses
- Nuts and seeds ?
- Tofu and tempeh
- Vegetarian meat alternatives like: mycoprotein, seitan and soya protein
- Protein supplements like: whey protein and pea protein
Calcium
Calcium is the main mineral found in our bones.
The recommended intake of calcium for adults in the UK is (4,5,6):
- 700 mg per day for most adults from the age of 19
- 1250mg per day for breastfeeding women
- 1200mg per day for post-menopausal women
- 1000mg for those who have osteoporosis, coeliac disease or inflammatory bowel disease
It is worth noting that the level of calcium in our blood are not usually a good indication of dietary calcium intake.
The best dietary sources of calcium are:
- Milk ?
- Yoghurt
- Cheese ?
- Malted milk drinks
- Tinned sardines (with bones)
- Calcium-fortified plant-based drinks (e.g. soya, oat or nut drinks)
- Calcium-fortified bread ?
- Tofu
- Rice pudding ?
- Dried figs
- Spinach ?
Calcium can also be found in slightly lower amounts in:
- Baked beans ?
- Cottage cheese
- Fromage frais
- Custard
- Ice-cream ?
- Calcium-fortified soya desserts
- Hummus
- Broccoli ?
- Brazil nuts
- Almonds
- Oranges ?
- Tinned salmon ?
Calcium supplements can be beneficial in some cases, but you should always get individual advice about this from a healthcare professional as this will depend on your diet, medication and use of other nutritional supplements.
Vitamin D
This is an important vitamin for bone health as vitamin D is needed for the absorption of calcium. In the UK it is estimated that 29% of adults are at risk of vitamin D deficiency (with serum vitamin D levels <25nmol/L), especially during the winter months (7, 8).
Vitamin D can be found in foods, such as:
- Egg yolks ?
- Oily fish ?
- Beef liver
- Mushrooms which have been grown under special lights ?
- Certain fortified foods like breakfast cereals, margarine, and plant-based drinks ?
However, it is difficult to consistently meet our vitamin D requirements from food sources in the UK. Therefore it is recommended that everyone over the age of 5 considers taking a daily supplement from October to March in order to meet our vitamin D requirements of 10 micrograms per day. More information about vitamin D supplements can be found on the NHS website.
Magnesium
Magnesium is another important mineral which is involved in bone formation. It is also needed by the body in order to absorb and process vitamin D properly, which has a knock-on impact on calcium levels.
The average intake of magnesium in the UK magnesium is thought to be below the recommended intake of 300mg per day for adult men, and 270mg per day for adult women (7).
Good sources of magnesium include:
- Pumpkin seeds
- Brazil nuts
- Soya beans
- Black beans
- Almonds
- Cashew nuts
- Sunflower seeds ?
- Spinach ?
- Wholemeal pasta ?
- Whole grain bread ?
It is best to get magnesium from our food rather than supplements where possible. Taking more than 350mg of magnesium in supplement form may lead to nausea, diarrhoea, cramps and possibly even heart problems (9). Higher doses of magnesium may also interfere with certain medication and compete for absorption with other minerals like calcium, iron and zinc.
Vitamin K
This vitamin helps to increase the rate that calcium builds up in the bones. The recommended daily intake of vitamin K is about 1 microgram per kg of body weight per day (10).
Most people in the UK reach their vitamin K requirements, as this is found in many foods including:
- Turnip
- Broccoli ?
- Collard greens
- Spinach ?
- Kale
- Green beans
- Beetroot leaves
- Brussel’s sprouts
- Dairy ?
- Meat and chicken ?
Although in certain cases it can be beneficial to bone health to supplement with vitamin K, these supplements need to be strictly avoided by anybody who takes blood thinning medication (like warfarin) (11).
Phosphorus
Phosphorus works in combination with calcium to form bone tissue.
Adults in the UK are recommended to have 550mg of phosphorus per day, and breastfeeding women require the higher amount of 990mg per day.
This mineral is present in a wide variety of foods including:
- Dairy ?
- Meat and poultry ?
- Oily fish ?
- Eggs ?
- Potato ?
- Whole grain bread, pasta and rice ?
- Oats ?
- Soya beans
- Baked beans
- Chickpeas
- Lentils
- Quinoa
Most people can easily get enough phosphorus from their diet. The UK Department of Health advise taking no more than 250mg per day in supplement form, as high doses of phosphorus can lead to stomach pain, diarrhoea or stomach and interference with calcium levels in the body (12).
Summary:
To optimise bone health it is important to consume the right combination of protein, calcium, vitamin D, magnesium, vitamin K and phosphorus.
This can be achieved through a balanced diet which includes a daily intake of: dairy, fruit, vegetables, beans, pulses, nuts, seeds and wholegrains; and a weekly intake of fish (including oily fish), meat, poultry and eggs. Those who don’t consume animal products can still achieve a bone healthy diet, although more dietary planning may be needed.
Supplements can be useful in certain circumstances, but you should always get advice from a registered health professional before starting supplements as there are risks and interactions to consider. Similarly, if you are worried about your diet and bone health, it is always best to seek individualised support from a Dietitian.
Along with a bone healthy diet, it is really important to include regular weight-bearing exercise in the week in order to strengthen the bones. This includes walking, running, bodyweight exercises (such as squats or push-ups), gardening, and even climbing the stairs or carrying shopping bags.
References:
(1) The NHS Website “Osteoporosis” [accessed September 2019 via: https://www.nhs.uk/conditions/osteoporosis/]
(2) Heaney & Layman (2008) “Amount and type of protein influences bone health” [accessed September 2019 via: https://academic.oup.com/ajcn/article/87/5/1567S/4650438]
(3) Alireza et al. (2016) “Timing, Optimal Dose and intake of dietary supplements”
(4) Department of Health (1991) “Dietary Reference Values for Food Energy and Nutrients for the United Kingdom”
(5) The Royal Osteoporosis Society “Calcium” [accessed September 2019 via: https://theros.org.uk/information-and-support/looking-after-your-bones/nutrition-for-bones/calcium/]
(6) Coeliac UK “Calcium” [accessed September 2019 via: https://www.coeliac.org.uk/information-and-support/your-gluten-free-hub/home-of-gluten-free-recipes/healthy-eating/calcium/]
(7) NDND “Years 1 to 9 of the Rolling Programme (2008/2009 – 2016/2017): Time trend and income analyses” [accessed September 2019 via: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/772434/NDNS_UK_Y1-9_report.pdf]
(8) SACN (2016)”Vitamin D and Health” [accessed September 2019 via: https://assets.publishing.service.gov.uk/government/uploads/system/uploads/attachment_data/file/537616/SACN_Vitamin_D_and_Health_report.pdf]
(9) The National Institute of Health “Magnesium” [accessed September 2019 via: https://ods.od.nih.gov/factsheets/Magnesium-Consumer/]
(10) The NHS Website “Vitamin K” [accessed September 2019 via: https://www.nhs.uk/conditions/vitamins-and-minerals/vitamin-k/]
(11) Cockayne et al. (2006) “Vitamin K and the prevention of fractures: systematic review and meta-analysis of randomized controlled trials” [accessed September 2019 via: https://www.ncbi.nlm.nih.gov/pubmed/16801507]
(12) The NHS Website “Others – Vitamins & Minerals” [accessed September 2019 via: https://www.nhs.uk/conditions/vitamins-and-minerals/others/]
