Your essential guide to Vitamin D
Posted on April 12 2019
Vitamin D is vital for strong bones, calcium absorption and immune function, but most of us still don’t get enough. Only a handful of foods contain significant amounts of this essential vitamin, which is why it’s key to read up and top up, to keep your body in the best condition possible.
What is Vitamin D?
Vitamin D is a fat-soluble vitamin that helps our bodies absorb calcium and phosphorus from our diets. When the body receives Vitamin D from sunlight, food, or supplements, it turns the Vitamin D into a hormone that plays an important role in our health and wellbeing. Vitamin D is known as the ‘sunshine vitamin’, because our bodies make most of the Vitamin D we need when our skin is exposed to enough UV light from sunshine.
Vitamin D has a few different forms, with Vitamin D2 and D3 being the two most important types for your health. Vitamin D3 is the most biologically active form and is regarded as the most effective because we can better absorb and use it.1
What does it do for our health?
Vitamin D is well known for supporting bone health, but it also has plenty of other benefits, too. It also helps keep teeth strong by ensuring we absorb and store enough calcium in our bodies, as well as having a positive effect on muscle condition.2 This promotes overall strength and can also help prevent skeletal problems in children and muscle weakness in adults.3
As vitamin D also has a positive effect on your vital organs such as the heart, liver, lungs and kidneys, it can help boost the immune system. It has effects on numerous cells and helps the body to produce over 200 antimicrobial peptides that help fight all sorts of infections. Vitamin D deficiency can lead to immunity problems and susceptibility to infection.4
Vitamin D also supports cardiovascular health. Recent scientific research suggests that vitamin D3 helps activate nitric oxide, which is a molecule that plays a vital role in the control of blood flow and formation of blood clots in blood vessels.5 The research also found that vitamin D3 significantly reduces oxidative stress in the vascular system.6 Not getting enough of this key vitamin could increase the risk of problems such as heart attacks and high blood pressure.
So, how do we get enough?
Vitamin D from sun exposure is the best way to optimize your vitamin D levels, but this is difficult unless you live somewhere with constant sunshine (if only!). However, even spending a lot of time in the sun often isn’t enough. This is because the suntan lotions we use to protect our skin from the damaging effects of the sun also make it difficult for us to absorb vitamin D. In colder months in the UK, we definitely don’t get enough UVB sunlight to make enough vitamin D, so as a result of this the NHS recommends taking a supplement to reduce the risk of a deficiency.7
Another way we can increase levels of vitamin D in our bodies is through the foods we eat. Although fatty fish like salmon, mackerel, and sardines provide us with some vitamin D, you would have to eat them almost every day to get enough of it. Most foods don’t contain much vitamin D so it’s hard to get enough from food alone, particularly if you’re vegan or vegetarian (most foods high in vitamin D are animal products). Again, this is where supplements come in. If you don’t get enough vitamin D, you should consider taking a high-quality vitamin D3 supplement each day to keep your body topped up.
What to remember
A vitamin D deficiency is one of the most common nutrient deficiencies, so keeping an eye on your intake is a good idea to keep your health in check. A quality supplement is a good place to start. Getting enough vitamin D by supplementing your diet will help prevent any problems a deficiency could lead to and will go a long way in boosting your overall health.
1 Tripkovic, L., Lambert, H., Hart, K., Smith, C. P., Bucca, G., Penson, S., … Lanham-New, S. (2012). Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis. The American journal of clinical nutrition, 95(6), 1357–1364.
2 Rejnmark L. (2011). Effects of vitamin d on muscle function and performance: a review of evidence from randomized controlled trials. Therapeutic advances in chronic disease, 2(1), 25–37.
3 Calcium/Vitamin D Requirements, Recommended Foods & Supplements. (2019). Retrieved from https://www.nof.org/patients/treatment/calciumvitamin-d/
4 Aranow C. (2011). Vitamin D and the immune system. Journal of investigative medicine: the official publication of the American Federation for Clinical Research, 59(6), 881–886.
5 Andrukhova, O., Slavic, S., Zeitz, U., Riesen, S. C., Heppelmann, M. S., Ambrisko, T. D., … Erben, R. G. (2013). Vitamin D is a regulator of endothelial nitric oxide synthase and arterial stiffness in mice. Molecular endocrinology (Baltimore, Md.), 28(1), 53–64
6 Khan, A., Dawoud, H., & Malinski, T. (2018). Nanomedical studies of the restoration of nitric oxide/peroxynitrite balance in dysfunctional endothelium by 1,25-dihydroxy vitamin D3 - clinical implications for cardiovascular diseases. International journal of nanomedicine, 13, 455–466.
7 The new guidelines on vitamin D – what you need to know. (2019). Retrieved from https://www.nhs.uk/news/food-and-diet/the-new-guidelines-on-vitamin-d-what-you-need-to-know/