When I started my nursing career in 1973, I was taught very little about nutrition. Vitamin D was to help calcium into the bones for growth and strength and really, it had very little other use. Also – it was called vitamin D only – not D2 or D3 as you may have heard more recently.
This is yet again, the problem with science – it seems helpful until the next bit of science comes along and changes everything. So at this time we are aware that there are two forms of vitamin D that have some importance for us as humans – D2 and D3. D2 is present in plants and not as bio-available to us as D3, which is obtained from animal sources and the sun. Another recent discovery is that in order for vitamin D3 to be used properly, vitamin K2 needs to be present. And vitamin A. And several minerals..
I named my business “Your Good Health – Naturally” for a very specific reason which I am sure you can guess. If we eat the diet we are programmed for and emulate (impossible to live the exact same life) the lifestyle we evolved with, we get what we need for life, health and reproduction. And this is in spite of the constantly changing “evidence” that science brings us.
I suspect that over the next decade, we will see vitamin D split into other analogues. New science is already showing that vitamin D from the sun is water soluble and can travel easily in the blood, but vitamin D from food is fat-soluble and in fact, needs fat for its absorption if it is contained in non fatty sources (eg. vegetables). I wonder how long it will take before science shows us that it is also used differently in the body!
It wasn’t so long ago in our history that we spent a great deal more time outside. Children played outside in all weathers. When I was young, we had two TV channels and no computers to keep us indoors. We saw the sun at all times of the day and no sun-screen was applied, since it hadn’t been invented. Sun-tan lotion (to attract the sun to make tanning quicker) was around in the 1960s as I remember and we were encouraged to be in the sun as it gave us vitamin D. What on Earth has gone wrong? People of the western world are now vitamin D deficient – to epidemic proportions. If we are to remain disease-free, things have to change.
So why do we need vitamin D? Before I address that, I must first emphasise that nutrients work together, not in isolation. The trouble is, when we hear that something is good for us, we then overdo it – “if some is good, more must be better”. We often buy supplements. but please, get professional help with this if you intend to take them. Vitamin D3 on its own can be harmful. Vitamin D3 helps the absorption of calcium but is is vitamin K2 that directs it to bones and teeth – away from arteries where it causes damage.
We now know that vitamin D3 (which is the form our bodies use easily) is needed for countless processes in the body. In fact, the bottom line is that we cannot live without proper levels of vitamin D.
(The UK RDA for vitamin D will protect against bone diseases but we need far more than this for optimum health. If half an hour in the sun can produce 20,000 units of vitamin D in our skin, the UK RDA, at a mere 2-400 units, is woefully inadequate.)
Children and babies have died from this deficiency and adults become ill and die from the diseases that are associated with the deficiency – but their conditions are rarely attributed to it as blood levels of vitamin D are not routinely tested. Due to all the known processes in the body where vitamin D3 takes a part, it is not difficult to imagine what might happen if it is not present in the needed amounts.
Immunity is compromised along with all that this entails: pathogenic infections are not effectively fought; potentially cancerous cells may not be destroyed; asthma and eczema are more prevalent as are other allergies; incidences of gut problems such as Crohn’s disease and ulcerative colitis are more evident as are the symptoms in established disease.
Interestingly, the incidence of malignant melanomas (which some authorities believe to be due to the sun’s rays) are less common in those with optimum levels. There are about twenty different types of cancer that are known to have a connection with vitamin D deficiency.
Bone density is severely compromised without adequate levels of vitamin D. Rickets is the name for this condition in children and osteomalacia in adults. Babies have been known to be born with the condition and their bones remain fragile instead of being strengthened by mineral deposits. This condition at its worst is incompatible with life. The condition is evident as the legs become bowed in children and adults. Osteoporosis is also a bone thinning disease where vitamin D deficiency may at least in part, be implicated. Don’t forget the K2 too!
It is now thought that vitamin D3 is involved with cholesterol regulation, the occurrence of mental disturbances such as dementia and depression, heart disease and the onset and progression of multiple sclerosis.
Such terrible consequences from a deficiency that is entirely preventable – for free. In Britain, during the months of April to September the sun rises high enough in the sky for the UVB rays (which are the ones needed to form vitamin D3 in our skin) to reach us here in the Northern Hemisphere. UVB rays are short in comparison to UVA rays – which are available from dawn to dusk. The easiest way to gauge if the sun is right is to look at your shadow. If it is shorter than you are tall, the UVB rays are present and you can strip off! Be sensible here – if your skin is fair, five minutes a side is sufficient. If you have black skin, you must start with about thirty minutes a side. Unfortunately, black-skinned people suffer the most in the Western world as it takes that much longer for the UVB rays to penetrate. It is none-the-less, absolutely vital they sunbathe if they are to stay healthy. The amount of sunshine needed to be effective, also depends where you are. The more northerly the position, the longer it will take and if you are on holiday in the Med, less time will be needed. Your skin should be slightly pink, not red. Do NOT go to sleep in the sun – you are very likely to burn! After this time, it is best to cover up or sit in shade but if you must, use a sunscreen that is as natural as possible. The usual sun-screens have many unpleasant and damaging chemicals in them. Your skin will quite happily absorb these into your body where they have absolutely no place. (Best to use water only for showering after sun exposure, to prevent washing away those precious skin oils.)
If your ancestors were from the Northern Hemisphere, you are adequately equipped for life here. The fact that our livers can store huge amounts of vitamin D means that even though there is no UVB sunlight during the winter months, we will be fine if we have adequate stores. If we haven’t, maybe a D3 and K2 supplement would be useful for a few months. Please seek advice regarding this.
People whose ancestry is nearer the Equator should take extra care. The storage space for vitamin D may not be the same as people from more northerly climes, due to the intensity, frequency and duration of sunlight in equatorial countries. Nature doesn’t change what it does very quickly, meaning that we have to.
There are many foods that contain vitamin D. D2 is present in leafy green vegetables but some people have trouble converting it to the D3 that is needed for humans and some other mammals. To maximise the absorption of D3 from plants, serve vegetables with a knob of butter or in a creamy sauce. Animal foods that are rich in D3 – eggs, full-fat dairy, offal, shellfish and other surface swimming fish. Meat (and especially offal) that has the highest levels of D3 will be from animals that are reared outside on pasture where they can eat grass and weeds that contain abundant D2 which they will convert to D3. These are foods that are nutrient-dense all round and should be included in our diet anyway.
In 2012 we had a lousy summer. During the winter of that year, I dropped my “no supplements” rule and took a D3/K2 supplement until April. Maybe there are some occasions when it is a good idea, as the above, but also you might want to do this if you have dark skin or if you have not been able to sunbathe much when the sun was out. To me though, ”naturally” is always the best.