BLOG
Vitamin D 'the sunshine vitamin'
· Why is vitamin D such a crucial vitamin?
Vitamin D is extremely important for our overall health and well-being, it is so crucial because it influences the development, function and maintenance of many organs and tissues in the body. We use vitamin D to make a hormone called calcitriol that regulates how much calcium is absorbed from the blood to maintain healthy calcium and phosphorous levels, necessary to grow and maintain healthy teeth, bones and muscles. Vitamin D plays a pivotal role in muscle function and strength including within the heart muscle. Aside from musculoskeletal health, more recent research has shown that it also helps regulate the immune system, lowering the risk of infection auto immune conditions and even cancer. We now know that Vitamin D helps activate T cells (the killer cells) in the body. T cells detect and destroy foreign pathogens like viruses. Making vitamin D essential for everyday immune defence especially going into winter.
· Why is the sun the best way to obtain it?
​
Food sources of vitamin D are limited, oily fish, beef liver, cheese and egg yolks contain small amounts. If you are vegetarian the only plant-based source is mushrooms, however these provide the D2 form which is less absorbed. Fortunately, our ingenious bodies have found a way of making its own, using sunlight. When our skin is exposed to ultraviolet B (UVB) rays it converts a cholesterol like substance present throughout the skin into a pre-vitamin D form. A protein then binds to the newly created vitamin D3 and transports it via the bloodstream to the liver and kidneys where it is converted into a form of D3 that your body can use. Isn’t the body amazing!!
Interestingly, the final stage of conversion from pre-vitamin D to vitamin D3 is temperature dependant. At temperatures at or near body temperature, the reaction can proceed for around three days, continuing even after sun exposure ends. Human skin temperature is normally lower than core body temperature and varies between approximately 29°C and 35°C. However, researchers found that at 37 degrees conversion dramatically decreased. Showing that the rate of vitamin D produced will, in turn, vary as skin temperature fluctuates.
Nature has built in this mechanism to avoid toxic levels from building up. Vitamin D taken through supplements is not subject to the same controls, so it is important to get a vitamin D test before you start supplementing. Exposure to ultraviolet B (UVB) sunlight is considered the most efficient way to boost vitamin D supply but it is still unclear how much sunlight is required to maintain a healthy blood vitamin D level (at least 20ng/ml) all year round to protect our muscle and skeletal health. A level less than 12 ng/ml indicates deficiency.
People who live at latitudes above 37 degrees north or below 37 degrees south of the equator make little if any Vitamin D in the winter months as there is not enough UVB to trigger Vitamin D synthesis in the skin. At 54 degree North the UK Population fall in this category and Public Health England advises that all adults should consider taking vitamin D supplementation of 400iu daily in the winter months to avoid deficiency.
· How common is deficiency these days and why is it so common? Does our modern way of living have an impact?
Over 1 billion people worldwide are estimated to be deficient in Vitamin D. Approximately 20 percent of the UK have a vitamin D deficiency and 60 percent of the population are considered as having insufficient levels of vitamin D. As such it is considered to be a global health issue.
Since the global pandemic individuals who used to work from home 46.6 percent of the week in 2019 have now increased this time to 86 percent of their working week in 2022. This increase in remote working has meant that many people are not even leaving the house from 9-5 and some would say that the lockdown culture has created a generation of agoraphobes. Being kept indoors for lengthy periods could be depriving us of the ‘sunshine vitamin’ we all so desperately need.
Modern technology has a lot to answer for as these days most children remain indoors on their games consoles rather than kicking a ball about in the garden. Low vitamin D levels are linked to bone conditions such as rickets in children and osteomalacia and osteoporosis in adults. Each year an estimated 1.5 million individuals suffer a fracture due to bone disease. Experts believe the lack of exposure to sun and reduced playtime outdoors are causative factors.
But it’s never too late! A recent study in Japan claims that osteoporosis can be reversed with sunlight exposure. Over 12 months 129 elderly, hospitalized women were exposed to regular sunlight while another 129 stayed indoors. The results were impressive. The sunlight group increased bone mass by 3.1 percent and in the non-sunlight group it decreased by 3.3 percent.
The modern day obsession with anti-aging, skin cancer fears and daily sunscreen could also potentially cause vitamin D deficiency. For those who practice rigorous protection, continually applying thick sunscreen, wearing photoprotective clothing, hats, staying in the shade when outdoors could have a higher risk. However, one Australian study found that adequate vitamin D levels were maintained over the course of the summer whether individuals used a broad spectrum sunscreen or a placebo. Dermatologists recommend practising sensible photoprotection and advise daily vitamin D supplementation.
· What signs might someone have if they are deficient and what health issues can they be more at risk of?
Vitamin D deficiency can be difficult to spot as one of the first signs is fatigue and tiredness which most of us dismiss as over work or burning the candle at both ends. But vitamin D deficiency may underpin a host of energy depleting ailments from depression to insomnia. A recent study examined the relationship between vitamin D and depression and found evidence that supplementation could be beneficial.
Another sign could be if you are experiencing frequent colds and infections. Vitamin D has a key role in supporting immune health helping defend against viruses and bacteria. Recent studies show that vitamin D deficiency has been linked to respiratory tract infections, bronchitis and pneumonia and increased risk of Covid 19. Researchers are suggesting inflammation is the culprit and that there is a direct link between low levels of Vitamin D and higher levels of an inflammatory biomarker called C-reactive protein (CRP).
As Vitamin D plays a crucial role in regulating calcium optimum Vitamin D is critical for bone health and muscle strength, back pain and muscle aches and pains could be a symptom of deficiency. As vitamin D regulates Vitamin D’s Role in Bone Health | OmegaQuant
Studies have shown that the people most at risk of developing vitamin D deficiency are children below 5 years old, pregnant, and breastfeeding women, overweight people, people over 65 years old, people with darker skin tones, and people who follow vegetarian or vegan diets.
· Would you recommend a supplement? And if so, what should people look for when choosing a supplement?
The Department of Health recommends taking a vitamin D supplement of 10 micrograms per day or 400iu.
- Conclusion.
Vitamin D is essential for good bone health and for most people sunlight is the most important source of vitamin D. The time required to make sufficient vitamin D varies according to a number of environmental, physical and personal factors, but is typically short and less than the amount of time needed for skin to redden and burn. Enjoying the sun safely, while taking care not to burn, can help to provide the benefits of vitamin D without unduly raising the risk of skin cancer. Vitamin D supplements and specific foods can help to maintain sufficient levels of vitamin D, particularly in people at risk of deficiency. However, there is still a lot of uncertainty around what levels qualify as “optimal” or “sufficient”, how much sunlight different people need to achieve a given level of vitamin D, whether vitamin D protects against chronic diseases such as cancer, heart disease and diabetes,