Calcium and bone health
We all know that calcium is a vital mineral for the development and maintenance of strong bones and teeth. This information is focussed on the role of calcium in bone health. However, calcium is also needed for other processes, such as muscle contraction, blood clotting and cellular signalling.
Generally, we reach our peak bone mass at around the age of 30. As we approach our mid to late 30s, we gradually start to lose bone mass and this is particularly relevant for women of menopausal age. Oestrogen protects against bone loss, by reducing bone cells being broken down and reabsorbed into the blood. At menopause, oestrogen levels drop and the rate of bone loss accelerates for about the next 5 to 10 years, before steadying to a gradual 1% loss per year.
Post-menopausal women are therefore a high-risk group for osteoporosis, which occurs when bone breakdown exceeds bone formation. Osteoporosis leads to brittle, fragile bones and an increased risk of fractures. It can also cause chronic pain and restricted movement. The best way to avoid osteoporosis is to achieve a good peak bone mass through dietary and lifestyle choices during the adolescent years. However, bone density can be improved at any time of life.
The calcium that we get through diet is stored in the bone, together with phosphate, in a mineral matrix called hydroxyapatite. Hydroxyapatite gives our bones and teeth strength and rigidity. If we do not consume and absorb sufficient calcium for bodily processes, calcium is pulled from the skeletal bone into the bloodstream to be used by the body. Over time if calcium stores are not replenished, our bones weaken, leading eventually to conditions such as osteoporosis.
In order for calcium to be efficiently absorbed and stored in the body, we also need other nutrients, such as Vitamin D3 and Vitamin K2. Vitamin D is predominantly synthesised when we expose our skin to sunlight, but can also be obtained through some foods. Vitamin K is obtained from foods.
Daily requirements of calcium vary according to life stage.
Adults under 50 require 1,000mg per day, over 50 this increases to 1,300mg. Phyto-oestrogens, exercise and increased magnesium and boron intake can support the body to store calcium. Whereas, factors such as a sedentary lifestyle, stress, smoking, alcohol and caffeine consumption can negatively impact our calcium stores.
These days many of us choose to reduce or eliminate dairy from our diets, for a variety of reasons. There are many alternative sources of calcium and I have listed my top dairy alternative sources below, for both vegetarians and those who eat meat. Additionally, some dairy free milk may be fortified with calcium, which can be a good option for those who need an additional source of calcium.
Food Portion size Calcium content
- Sardines (in oil) 100g 382mg
- Pink salmon (canned) 100g 277mg
Green leafy vegetables:
- Collard greens 1 cup 268mg
- Spinach 1 cup 245mg
- Kale 1 cup 172mg
- Sesame seeds 1 tablespoon 88mg
- Tahini 1 tablespoon 64mg
- Almonds 10 almonds 30mg
- Almond butter 1 tablespoon 43mg
For more ways to support your bone health, please speak to your healthcare professional. The Urban Herbalist are currently offering free bone mineral density scans with an initial consultation until the end of September 2018, or bone mineral density scan appointment for just $45. To make a booking with Suzy, please visit https://urbanherbalist.co.nz/pages/consultations.
By Suzy Walsh, Registered Naturopath & Medical Herbalist at the Urban Herbalist, Orakei Bay Village