Sunshine, Vitamin D, and Health

Ahh, Summer. Long days, balmy nights, beaches and barbeques and fun in the sun. Don’t you just love it?

One of my favourite aspects of this season – frivolities aside – is the opportunity to load up on Vitamin D, that magical thing bestowed upon us from the sun itself. So, in tribute to this wee beauty, today’s blog is going to be dedicated to the wonders of this oft-forgotten yet utterly vital piece of the health puzzle.

So, what is Vitamin D?

Vitamin D is a vitamin-like compound (technically speaking, it’s a hormone) produced in the oils of our skin when they come into contact with sunlight, or more specifically, UV-B rays. It can’t be synthesised when the skin has anything else on it – whether that be clothing, sunblocks (either chemical or physical), moisturisers, nor will it be produced when the sunlight passes through glass. Direct sun is where it’s at!!

There are a few things to be aware of, however, when working towards your daily fill of the sunshine vitamin.

Firstly, UV-B rays don’t reach the Earth year-round, except for at latitudes around the equator. In New Zealand, the sun’s rays are at such an angle as to make production of Vitamin D near impossible between roughly April to August, depending on how far north or south you are. During the months it is available from the sun, these UV-B rays are only at the correct angle for production between the hours of roughly 10am to 2pm, when we’re all told to cover up the most! For this reason, many kiwis are seriously low in vitamin D – however, the sun-smart message shouldn’t go out the window and you should never let yourself burn, as will be discussed later on. This means that winter sun generally won’t do much for your D levels, and you need to ‘stock up’ in summer. Lucky for us, Vitamin D is one of the fat-soluble vitamins, meaning the body can store it – unlike Vitamin C and the B group, which are water-soluble and therefore need replacing via the diet on a daily basis.

Secondly, skin tone, type, and colour also play a role in how much we make. People with very pale, fair skin will produce their D in a much shorter timeframe than those with darker skin, who have more melanin present which is nature’s built-in sun filter. For somebody with blue eyes and very pale skin, it may take just 10 minutes to produce adequate vitamin D for the day, whereas somebody with very dark skin and brown eyes may take up to an hour or two to produce the same amount. This largely comes down to ancestral homes – people from areas closer to the equator have a higher melanin content in their skin to help protect against the increased sunlight and intensity found there, whereas those from latitudes farthest from the equator have minimal melanin, as they need to produce all the Vitamin D they can and have a much lower need for sun protection.

Altitude (the higher you are, the more Vitamin D you’ll receive), pollution, and age are all other factors that can impede production of D. Elderly people tend to have lower levels of the substance found in the skin’s oils that assist absorption – and some steroids can also impede production. Magnesium, Vitamin K (from green leafy veges), boron, and zinc are all also needed to properly use it, so it’s important to ensure you’re eating a healthy, balanced diet, based largely around whole foods such as vegetables, fruits, soaked nuts and seeds, and if you choose to eat animal products, free-range and preferably organic animal products.

Thirdly, we need to also be aware of the old ‘sun smart’ catch-phrase, and yes, still be smart about things. The number one rule, as ever, is not to let yourself burn, as this is where skin damage occurs – and it also means the Vitamin D, which is produced in the oils of the skin and absorbed over time, will be burning off, making the entire effort a waste of time. It takes roughly half as long to produce your daily vitamin D needs as it does to burn, so don’t be silly about things, especially given the intensity of the sun here with that whopping great ozone hole over Antarctica!

So why is Vitamin D so important?

For lots of reasons. Vitamin D plays a role in myriad functions in the human body. For a start, it is an excellent modulator and ‘booster’ of immunity – and research suggests it can be protective against illness and frequent infections, including influenza and respiratory disorders, particularly during winter. It is also necessary for strong, healthy bones, as it is needed for the body to properly use calcium and to create strong bones and teeth. Deficiency has been linked to a number of serious health disorders, ranging from the classic Vitamin D deficiency disorder rickets, common during the 19th century and experiencing an alarming re-emergence in recent years, through to mental health disorders such as depression, Seasonal Affective Disorder, autoimmune disorders, chronic infections and low immunity, Multiple Sclerosis, Autistic Spectrum Disorder (autism), Schizophrenia, various cancers, and other serious health complaints. Deficiency of Vitamin D during pregnancy in particular is linked to onset of ASD and schizophrenia.

It is also important to note that in New Zealand, and much of the developed world, Vitamin D deficiency has hit critical levels, with a large percentage of the population very deficient in this extremely important vitamin, especially during the months of winter and spring, when production from the sun is at its lowest. Levels can be checked by simple blood tests available through your GP, however many labs are no longer testing people’s levels, as the test is expensive and the vast majority of people are deficient. Speak to your doctor about having your levels checked if you are worried.

During winter, and during pregnancy, supplementation is often recommended by health practitioners to ensure adequate levels. If supplementing is desired, always use a Vitamin D3 supplement, which is the form the body can use – vitamin D2 is not easily utilised. 1,000-5,000IU per day is the general guideline for an adult; however, your health practitioner (doctor, naturopath, nutritionist, or other) will be able to give better specifics for your individual needs. It can also be a good idea to have your levels monitored every few months during supplementation, as being a fat-soluble vitamin, toxicity is theoretically possible and can create other health complications. Too much of a good thing can be a bad thing! It is also worth noting that Vitamin D is found in a number of animal products, including eggs, (grass-fed) butter, and cod liver oil, so for non-vegans these can be a useful food source of the vitamin.

So there you have it – a rough overview of this magical little product most of us will need more of. An all-round bone-strengthening, health-inducing, immune-boosting, joy-bringing gift from the sun to help us feel great year-round.

Enjoy your summer.



*References available on request