London, quite surprisingly, is on the same latitude as Calgary in Canada. Despite London’s far milder winters, thanks to the Gulf Stream, we receive fewer hours and weaker sunshine than this Canadian ski resort and home of a former Winter Olympic Games! We are so far north that if the Gulf Stream ever stops (looking at you global warming), we may see icebergs on the river Thames.
But it’s not just in London that sunshine is lacking, the peoples of the world have settled all over this planet, many live some distance from the equator where sunlight is weaker and less frequent. Modern life has moved us inside, with dull, artificial lights.
This loss of sunlight, leads to a loss of a vital vitamin, that plays a significant part in calcium uptake and bones; avoidance of cancers and autoimmune disease; improved mood and sleep; and protection from dementia. Since depression, SAD and poor sleep are all too common in ADHD, we should focus more on vitamin D, the sunshine vitamin. Well actually Vitamin D is a hormone but we will stick with the vitamin name.
So can you eat vitamin D in your diet?
The British Scientific Advisory Committee on Nutrition (SACN), is now advising a daily intake of vitamin D of 10 micrograms (400 IU) vitamin D every day. Previous assumptions were most people would have enough exposure to sunlight to reach this target, but latest scientific evidence has shown that “this is not the case”. Most people currently get less than 5 micrograms of vitamin D daily from their diets.
Vitamin D is the odd one out, around 90% of our Vitamin D comes from sunshine not from food. It is actually a hormone not a vitamin. When ultraviolet-B rays fall on our skin, the interaction of UVB light with a cholesterol derivative causes vitamin D to be synthesized in the body.
We get meagre amounts from food, such as fish, eggs and milk. Vitamin D2, is added to less-than healthy foods like margarine and breakfast cereals. The official daily guideline, for vitamin D is 400 IU (10mcg), that’s either 20 eggs (20 IU each), more than a litre of fortified milk, 5oz/140g salmon, (more like 20oz/560g of farmed salmon!!) or 1lb /450g tinned tuna (well they remove the good oil before tinning).
Some experts put the daily recommended D3 intake much higher at 10,000 IU, that’s a lot of eggs. It’s very hard to get enough vitamin D from food alone.
It has been very obvious from the arrival of Covid-19 that Vitamin-D is significantly protective against the virus. Not surprising as it is so involved in our immune systems. The worst impacted groups for mortality also tend to have the lowest Vitamin D levels and recent double-blind studies are showing a more than 50% reduction in mortality with sufficient Vitamin D levels. Generally the recommendation is to take a high dose from 3000-5000IU per day but obviously I am not a doctor, please do your own research on this. You could start checking out
Why not just soak up those vitamin D producing sun rays?
If not from food, then why not from sunshine? There are a few problems with sunbathing to health too:
- Too north, or south. As with London, much of the world’s population live either too far north or too far south of the equator, for winter sunshine to be of much use. Studies suggest people living above 37 degrees north, or below 37 degrees south of the equator, don’t get enough UVB energy to make sufficient vitamin D.
- Glass ceiling. You must be outside to produce vitamin D3, as glass absorbs ultraviolet-B UVB light. No vitamin D effects in your conservatory, car or greenhouse.
- Skin cancer. Much cancer advice recommends avoiding peak rays and using sun creams, opposing Vitamin D advice to strip off and get exposed. Very confusing.
- Interior living. From a couple of centuries ago, we are down from 90% farmers to less than 2%. Most work inside, drive cars, take trains and sit at home with short walks outside in clothes! Collectively we spend less time outside in nature, it’s a shame.
Vitamin D chemistry
Recipe for a fair skinned person. This makes enough vitamin D, 7,000 IU, for the week in the UK. To get enough ultraviolet-B:
- Get outside in mid-summer
- Face and forearms exposed
- Around midday
- Rest 20-30 minutes in sun’s rays
- Repeat 3 times/week
If older or darker skinned, you may need ten times that exposure. To get enough UVB would involve
- Get outside in mid-summer
- Face, forearms, legs exposed
- Around midday
- Rest 3 hours in sun’s rays
- Repeat 5 times/week
That’s a long and possibly embarrassing lunch-break, sat in the office car park or local park, dressed in shorts and a tank top, hoping the clouds will part.
For many people getting enough sunlight is impossible. In the summer months, we can build some vitamin D reserves but on cloudy days or in the winter months when there is insufficient light to produce vitamin D, our reserves run down. In an American study researchers found deficiencies in 41% of non-hospitalized patients and 57% of hospitalized patients.
In winter, we don’t get enough vitamin D from food or from the sun’s rays.
Yes, that seems to be the general conclusion being formed around the world. Vitamin D supplements are by law added to foods like milk in several countries. Researchers and governments consistently make strong recommendations for more. The simple solution is to take a vitamin D supplement.
Benefits of vitamin D supplements
Vitamin D is an amazing protective chemical available in spray, liquid and capsule. The preferred form is vitamin D3, not D2, and vitamin D3 is now available in lichen or mushroom vegan form too. It protects against heart, eye and bone problems, against cancers, autoimmune diseases, depression and improves sleep quality.
One pill a day to gain so many benefits. For me it keeps my SAD away during the winter months. Amazing vitamin D can bring sunshine to the cloudiest day…