Calcium.
Calcium is the most abundant mineral in the body and every body requires different amounts. These may vary over time, and sometimes can vary depending on health but minerals (inorganic substances) are required by the body to function, albeit in small amounts.
Calcium is essential for healthy, strong bones and teeth, as well as for the nervous system and muscle function, intracellular signalling and blood clotting. The body carefully controls calcium blood plasma levels, and does so by balancing absorption in the gut, excretion in the kidneys and by mobilising/depositing bone stores, with approximately 99% of bodily calcium stored in the skeleton. This is important because ordinarily a deficiency may be detected when blood levels fall below an accepted level. However, due to the tight regulation of calcium in the blood, the body will replenish blood levels from the skeleton, potentially compromising bone density. Bone density can also be compromised if there is insufficient vitamin D, as that is essential for calcium absorption (UK folxs take a vitamin D supplement – 10mcg, September to April).
As well as Vitamin D, dietary protein promotes absorption, so think about eating foods in combination, rather than in isolation. The calcium present in animal dairy is more readily absorbed than from plants for a few reasons, one of which being the phytates and oxalates that occur naturally in these foods that bind to the calcium and prevent us from absorbing it (they do the same with iron). However, foods such as broccoli have a much better bioavailability (how much is available to absorb)
It’s important to remember that diet isn’t the only thing that impacts health, and bones are no different. Healthy bones benefit from a bit of activity – weight bearing exercise such as walking, aerobics and running are linked with improved bone density and smoking is linked with decreased bone density.
The latest NDNS data shows that there is a likelihood of a number of the population not receiving adequate intake (10% of adults and 16% of teenagers). The recommended adult (19-50yrs) intake in the UK is 700 mg/day, based on a healthy population, and there are some easy ways to improve calcium intake through food as there are many other benefits from consuming these foods, and supplements may not be the best option.
Some foods are fortified, meaning that nutrients are added (that are not normally present) with the aim of improving the nutrient status of a population, or in other words, it’s a good thing! White bread is fortified with calcium by law, and so can form an important part of the diet despite the fearmongering around refined carbohydrates! Cereals are often fortified as it is voluntary so always check the label. If you don’t consume animal dairy, or are vegan there are many plant-based milks available to buy but it is important to check the labels. Not all plant milk is fortified, and as such does not contribute to calcium intake – and this is a really easy way to add in extra calcium every day. Other great sources include green leafy vegetables such as broccoli and fortified soya products (look for calcium-set). There is a really useful guide here on calcium per portion from the British Nutrition Foundation.
If you are unsure about your calcium intake, or have a questions about your health please contact your GP or a registered health care professional, Nutritionist or Dietitian.
References:
Department of Health, Dietary Reference Values for Food Energy and Nutrients for the United Kingdom, HMSO, 1991.
EFSA Panel on Dietetic Products, Nutrition, and Allergies (NDA); Scientific Opinion on the Tolerable Upper Intake Level of calcium. EFSA Journal 2012;10(7):2814.
SACN Vitamin D and Health, 2016.
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