As children go through various growth spurts and milestones, it is vital to support healthy bones in order to provide them with a healthy foundation for their active childhoods, supporting them through play, sports, and all sorts of adventures. Knowing more about the correct nutrition needed to support healthy bone development can be a handy tool when planning meals. This article will delve into four of the most important vitamins to help children develop strong bones and how these can be easily implemented into their diets.
Key vitamins for bone health
Calcium not only forms the very structure of bones but also has many other roles, including in the functioning of the heart and nerves. Having enough calcium intake during childhood contributes to proper bone density formation and reduces the risk of fractures and bone-related issues later in life.1
One way of increasing calcium in the body is by eating calcium-rich foods or taking calcium supplements if needed. Approximately 99% of calcium is stored in bones and teeth, so if there is not enough calcium intake, your body can start to draw calcium from bones and teeth, resulting in weaker bones.2 It is therefore essential to know how best to increase calcium stores in the body through the diet.
Some sources of dietary calcium are
- Dairy products, including milk, cheese, and yoghurt
- Calcium-fortified plant-based milks such as almond and soy milk
- Leafy vegetables, including kale and bok choy
- Fish with bones, such as sardines and tinned salmon3
The recommended daily intake of calcium increases with age, especially in children, as their bones grow larger and stronger. The recommended daily intake of calcium for each age range is
- Under 1 year: 525mg
- 1-3 years: 350mg
- 4-6 years: 450mg
- 7-10 years: 550mg
- 11-18 years: 800mg for girls, 1000mg for boys
Vitamin D is essential for calcium absorption, meaning that increasing dietary calcium isn’t enough without also increasing vitamin D intake. Beyond its role in calcium absorption, vitamin D also influences muscle function and the immune system, making it a vital nutrient for overall health.4 Insufficient vitamin D intake can lead to weakened bones and an increased risk of bone-related issues like rickets.
You may have heard that the best source of vitamin D is from sunshine. This is true! However, there are other factors which limit how well your body can create vitamin D, including living in certain cloudier countries or having darker skin.5 In the UK, almost 20% of children now have low levels of vitamin D. Therefore, it’s important that children eat food rich in vitamin D whilst also combining this with moderate exposure to sunlight.
Some sources of vitamin D are
- Oily fish, e.g., salmon, mackerel, and sardines
- Red meat and liver
- Cod liver oil
- Egg yolk
The recommended daily intake of Vitamin D for children is as follows:
- Under 1 year: 8.5-10 micrograms a day
- 1 year and above 10 micrograms a day.
Vitamin K is most known for its function in helping blood to clot. However, increasing research is showing that vitamin K can help to increase bone mineral density and reduce the chances of fracture. There are some studies which have shown that vitamin K and vitamin D may actually help each other function better.6
Some sources of vitamin K are
- Green leafy vegetables, e.g., collard, spinach, kale, and broccoli
- Vegetable oils
- Cereal grains like oat and buckwheat
Recommended daily intake of vitamin K by age group:
- 1-3 years: 30mcg
- 4-8 years: 55 mcg
- 9-13 years: 50 mcg
- 14-18 years: 75 mcg
Vitamin C is most commonly known for its role in boosting the immune system and healing wounds, but it is also a powerful antioxidant and helps to make collagen, which is found in cartilage and bone.7 A lack of vitamin C can lead to a condition called scurvy.
Research on vitamin C and bone health is not as well-known as that on previously mentioned vitamins. However, there is increasing evidence that vitamin C induces bone cell formation and decreases bone loss.8
Some sources of vitamin C are
- Citrus fruits, e.g., oranges, lemons, and grapefruits
- Berries, e.g. strawberries
- Cruciferous vegetables, e.g. broccoli, brussels sprouts, and cabbage
Recommended daily intake of vitamin C by age group:
- 1-13 years: 15 to 45 mg
- 14-18 years: 65 to 75 mg.9
Factors affecting vitamin absorption
Sun exposure and vitamin D synthesis
Although vitamin D is produced in the presence of sunlight, there are several factors that affect exactly how well our body can do this. These include geographical factors such as location, the time of day or year, and also skin colour. People with lighter skin tend to produce vitamin D more efficiently compared to those with darker skin.10 This is because melanin, a pigment responsible for skin colour, acts as a natural sunscreen and reduces the skin's ability to produce vitamin D.11
Modern lifestyle patterns and increased indoor activities mean that children spend a lot of time indoors and may, therefore, be missing out on the opportunity to benefit from the natural power of sunlight. However, it is important to note that there are risks from excessive sun exposure without proper protection that can lead to harmful effects, such as sunburn and an increased risk of skin cancer. Therefore, a balance of regular sun exposure by encouraging outdoor activities alongside dietary sources can help ensure adequate levels of vitamin D for your child.
The role of physical activity in bone health
Exercise plays a significant role in maintaining bone strength as we age, with evidence that physical activity helps to prevent the development of osteoporosis.12 However, studies have shown that bone and muscle growth was increased in children who started exercising regularly before puberty, compared to non-active children.13 Therefore, being active during childhood can help grow healthy bones, supporting health throughout life.
Common bone health issues in children
Rickets is a condition that affects bone development, most commonly around 6 months to 2 years of age and in teenagers between 12-15 years old.14 It commonly presents with soft bones, leading to skeletal problems such as bowed legs. It can also lead to delayed growth and difficulty walking. Rickets used to be more widespread, but due to increased awareness and the increase of vitamin D supplementation in foods, the incidence has significantly reduced worldwide. However, it is still an important condition to keep in mind while your child grows.
- Vitamin D deficiency
- Calcium deficiency
- Genetic diseases that affect vitamin absorption
Treatment and prevention
- Vitamin D and calcium-rich foods as part of a healthy, balanced diet
- Vitamin D supplementation
- Sunlight exposure
Osteoporosis is a condition of brittle bones where bone creation cannot keep up with bone loss and usually presents with fractures. It is most commonly considered to be a condition affecting older adults, but childhood and adolescence are critical periods for bone growth, as nearly 90% of peak bone mass is formed during this time.15 There are also rarer cases of juvenile osteoporosis in which weaker bones happen at a younger age. It is, therefore, vital to start focusing on bone health from a young age to build a solid foundation for later years.
Causes and risk factors
- Low calcium intake
- Health conditions affecting absorption, e.g., coeliac disease
- Lack of regular physical activity
Preventative measures for strong bones
- Encouraging regular weight-bearing exercises like running and jumping
- Limiting sedentary behaviours
- Calcium-rich foods
- A balanced diet with other bone-strengthening vitamins
The role of healthcare professionals
The role of healthcare professionals in promoting bone health in children is vital for ensuring your child is growing and developing at the right rate. Regular check-ups and bone health assessments by paediatricians, especially if you have concerns, can help to identify any issues with bone development early on. This will allow for early intervention and prevention of conditions such as rickets or osteoporosis.
Paediatricians or nutritionists can provide parents with personalised advice tailored to their child's specific needs and current bone health. They will be able to recommend dietary and lifestyle choices and help you incorporate this into your child’s daily life.
Healthcare professionals can also provide a safe and informative space to educate parents and caregivers on healthy bone growth and their role in supporting their child’s development. This education will likely encompass the importance of a balanced diet, sufficient exposure to sunlight, and strategies to minimise sedentary behaviour to promote an active lifestyle. Empowering parents and caregivers will allow us to work together to ensure that bone health is prioritised in children, which can benefit them for years to come.
Ensuring strong bone health in children requires an understanding of the importance of vitamins, particularly calcium, vitamin D, vitamin K and vitamin C in their development. Understanding how we can introduce these naturally into their diet and lifestyle and factors that might affect their absorption will allow you to feel confident in supporting your child’s bone health.
Proactive measures, such as regular check-ups and bone health assessments, aid in the early detection of any potential issues and prevent any complications. Consulting paediatricians or nutritionists for personalised advice can empower you to make informed dietary choices and create an environment that will support healthy bone development. By prioritising bone health in children, we set the stage for healthy growth and a brighter future.
- Pan K, Zhang C, Yao X, Zhu Z. Association between dietary calcium intake and BMD in children and adolescents. Endocrine Connections [Internet]. 2020 Mar 1 [cited 2023 Jul 24];9(3):194–200. Available from: https://ec.bioscientifica.com/view/journals/ec/9/3/EC-19-0534.xml
- Avenue 677 Huntington, Boston, Ma 02115. The Nutrition Source. 2020 [cited 2023 Jul 26]. Calcium. Available from: https://www.hsph.harvard.edu/nutritionsource/calcium/
- Calcium - an overview | sciencedirect topics [Internet]. [cited 2023 Jul 26]. Available from: https://www.sciencedirect.com/topics/food-science/calcium
- Khazai N, Judd SE, Tangpricha V. Calcium and vitamin d: skeletal and extraskeletal health. Curr Rheumatol Rep [Internet]. 2008 Apr [cited 2023 Jul 24];10(2):110–7. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2669834/
- Vitamin d and calcium [Internet]. [cited 2023 Jul 24]. Available from: https://www.hopkinsmedicine.org/health/wellness-and-prevention/vitamin-d-and-calcium
- Weber P. Vitamin K and bone health. Nutrition [Internet]. 2001 Oct 1 [cited 2023 Jul 24];17(10):880–7. Available from: https://www.sciencedirect.com/science/article/pii/S0899900701007092
- Avenue 677 Huntington, Boston, Ma 02115. The Nutrition Source. 2012 [cited 2023 Jul 25]. Vitamin c. Available from: https://www.hsph.harvard.edu/nutritionsource/vitamin-c/
- Malmir H, Shab-Bidar S, Djafarian K. Vitamin C intake in relation to bone mineral density and risk of hip fracture and osteoporosis: a systematic review and meta-analysis of observational studies. British Journal of Nutrition [Internet]. 2018 Apr [cited 2023 Jul 25];119(8):847–58. Available from: https://www.cambridge.org/core/journals/british-journal-of-nutrition/article/vitamin-c-intake-in-relation-to-bone-mineral-density-and-risk-of-hip-fracture-and-osteoporosis-a-systematic-review-and-metaanalysis-of-observational-studies/E1229B088231CD96AE676352030F428B
- Trapani S, Rubino C, Indolfi G, Lionetti P. A narrative review on pediatric scurvy: the last twenty years. Nutrients [Internet]. 2022 Feb 6 [cited 2023 Jul 25];14(3):684. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC8840722/
- Jablonski NG. Chapter 3 - the evolution of human skin colour and vitamin d. In: Feldman D, editor. Vitamin D (Fourth Edition) [Internet]. Academic Press; 2018 [cited 2023 Jul 26]. p. 29–44. Available from: https://www.sciencedirect.com/science/article/pii/B9780128099650000033
- Bonilla C, Ness AR, Wills AK, Lawlor DA, Lewis SJ, Davey Smith G. Skin pigmentation, sun exposure and vitamin D levels in children of the Avon Longitudinal Study of Parents and Children. BMC Public Health [Internet]. 2014 Jun 12 [cited 2023 Jul 26];14(1):597. Available from: https://doi.org/10.1186/1471-2458-14-597
- Pinheiro MB, Oliveira J, Bauman A, Fairhall N, Kwok W, Sherrington C. Evidence on physical activity and osteoporosis prevention for people aged 65+ years: a systematic review to inform the WHO guidelines on physical activity and sedentary behaviour. International Journal of Behavioral Nutrition and Physical Activity [Internet]. 2020 Nov 26 [cited 2023 Jul 26];17(1):150. Available from: https://doi.org/10.1186/s12966-020-01040-4
- Vicente-Rodríguez G. How does exercise affect bone development during growth? Sports Med. 2006;36(7):561–9. Available from: https://pubmed.ncbi.nlm.nih.gov/16796394/
- World Health Organization. Nutritional rickets: a review of disease burden, causes, diagnosis, prevention and treatment [Internet]. Geneva: World Health Organization; 2019 [cited 2023 Jul 28]. Available from: https://apps.who.int/iris/handle/10665/329859
- Benjamin RM. Bone health: preventing osteoporosis. Public Health Rep [Internet]. 2010 [cited 2023 Jul 27];125(3):368–70. Available from: https://www.ncbi.nlm.nih.gov/pmc/articles/PMC2848259/