Most of us are well aware of the importance of calcium for bone density, but did you know there are over 20 different vitamins and minerals that have been connected to bone health? Whilst calcium is undoubtedly important for the bones (and also the most abundant mineral in the human body), insufficient intake of these other nutrients can also lead to reduced bone density, regardless of one’s calcium intake. This is a concern as it is a risk factor for conditions like osteopoenia and osteoporosis, putting individuals at risk of weak, brittle bones, especially as they age.
In this article today, we’ll be taking a look at some of the other main players in the world of nutrition and bone density.
After calcium, vitamin D is perhaps the most-well known for bone health – but what exactly does vitamin D do when it comes to calcium and your bones? Well, vitamin D directs the absorption of calcium from the small intestine, so it can enter the blood and eventually make its way towards the bones. Vitamin D also helps regulate calcium levels in the blood. When vitamin D levels are low, calcium absorption and metabolism is compromised, increasing the risk of conditions like osteomalacia and osteoporosis.
Sources of Vitamin D: Whilst vitamin D is found in foods like cod liver oil, egg yolks, salmon and oysters, most Australians get their vitamin D from the sun. Unfortunately however, despite being ‘the sunburnt country’, more than 30% of Australian adults have a mild, moderate or severe vitamin D deficiency, which overtime, puts them at significantly increased risk of bone disease. Why is this? Well, there are various reasons, but one of the main reasons is that we can only get vitamin D from the sun at certain times of day and at certain of year, depending on our location. At Perth’s latitude, we only get sufficient UVB rays for endogenous vitamin D production from around November to April, throughout the middle of the day. Of course, this is the time most Aussies are inside, at work or avoiding the sun, meaning maintaining sufficient vitamin D levels can become a challenge (especially whilst also ensuring adequate sun protection measures). For this reason, we monitor our patients’ vitamin D levels and in some case, may recommend supplementation, when adequate vitamin D levels cannot be maintained year round through food and sun exposure alone.
If you’ve been reading our blog for a while, you may have read our previous post about vitamin K2 and how it’s a super nutrient for bone density and anti-ageing. Whilst vitamin D is involved in regulating absorption of calcium, vitamin K2 directs that absorbed calcium into the bones, to keep them strong and healthy. It does this by activating a protein called osteocalcin, which ensures the calcium is deposited into the bones, as opposed to other areas of the body. In a way, vitamin K2 can be thought of as the traffic controller that tells the blood where to deposit the calcium. This is why vitamin K2 is so crucial – it ensures the calcium in your diet and/or supplements is deposited where it should be!
Sources of Vitamin K2: Whilst vitamin K1 is found in many food (like green leafy veggies), there are only a few dietary sources of vitamin K2. These include egg yolks from pasture-raised hens, dark chicken meat, and butter from grass fed cows. The reason these foods must come from pasture-fed sources, is that the animals consume vitamin K1 from the grass, and bacteria in their guts then convert it to vitamin K2 – the type of vitamin K required for bone health. Another food source of vitamin K2 is natto, a traditional Japanese food made from fermented soybeans. As these foods are not typically consumed in large amounts, vitamin K2 supplementation is beneficial for some individuals, to reduce their risk of osteoporosis. If you’re unsure whether vitamin K2 may be helpful in your case, chat to your naturopath about it at your next appointment.
Along with calcium and phosphorous, magnesium is one of the most abundant minerals in bone, with about 60% of your body’s magnesium content stored in your skeleton. Animal studies suggest magnesium increases osteocalcin levels (helping direct calcium towards the bones) and improves bone strength and resistance to fractures. In humans, magnesium intake has also been positively correlated with bone density, meaning individuals who consume more magnesium have better bone density levels. Conversely, magnesium deficiency alters bone crystal formation and is also associated with low-grade chronic inflammation, which is a known risk factor for bone loss.
Sources of Magnesium: Magnesium is found in various wholefoods, such as raw almonds, cashews, walnuts, pumpkin seeds, kidney beans, lentils, tofu, split peas, cacao powder and dark green leafy vegetables.
Of all minerals in the human body, zinc is involved in the most bodily functions and cellular processes, and many of these affect our bone density. For example, in the digestive tract, zinc is needed to produce stomach acid. This is fundamental to bone health, because an acidic stomach environment is crucial for the absorption of minerals like calcium. This is, in part, one of the reasons long-term antacid use can contribute to reduced bone mineral density.
Zinc is also needed to produce the structural matrix into which minerals like calcium and phosphorous are deposited in the bones. It stimulates the activity of bone-producing cells (known as osteoblasts) and regulates the activity of osteoclasts (the cells responsible for bone breakdown). Overall, low levels of zinc have been linked to increased risk of osteoporosis and increased risk of fracture, particularly in women.
Sources of Zinc: Sources of zinc include red meat, eggs, oysters, lamb, pumpkin seeds, hemp seeds, lentils and cashews.
Whilst scientific understanding of the role of silicon in bone health is increasing, it’s an area researchers are still learning about as they discover the various ways in which silicon appears to affect the bones. Whilst silicon supplementation has been shown to increase bone volume and bone mineral density in both animal and human studies, the mechanisms by which these improvements occurred are not fully understood. It has been suggested that silicon plays a structural role in the bones, by forming crosslinks with proteins like collagen, which contribute to improved bone density. Silicon also appears to increase calcium incorporation into the bones, in essence, making them more ‘calcifiable’.
Sources of Silicon: Dietary sources of silicon include carrots, green beans, wholegrain cereals and other root vegetables. Whilst silica is sometimes added to food in the form of various food additives, this form is poorly absorbed.
Other Food Components and Factors Affecting Bone Density
Many other food components have been identified for the various roles they play in bone health. This includes compounds like phyto-oestrogens, flavonoids, antioxidants and other phyto-chemicals. When working with patients to prevent bone loss and promote healthy bone density, we look not only at the vitamins and minerals they’re consuming, but also at these other food components, which can play an incredibly useful role. Some of the other nutrients we haven’t explored in this article include things like boron, phosphorous and manganese, which all play their respective roles in bone health.
When working with patients to improve bone density, we explore and investigate potential nutritional deficiencies, in addition to using blood tests to ensure other factors affecting bone density are accounted for (such as thyroid function, vitamin D status and hormones like oestrogen). We also consider factors like absorption and digestive function, to ensure nutrients are being taken up from the digestive tract, as well as whether the patient is engaging in regular weight-bearing exercise, as this is linked to improved bone density. Lastly, we teach our patients about something called the Potential Renal Acid Load of foods, so they can ensure their diet has a net alkalising (and therefore bone-protective) effect!