Smorgasbord Health Column – UnSeasonal Affective Disorder – The Missing Link – Vitamin D by Sally Cronin

Normally I would refer to Seasonal Affective Disorder in February as the winter months take their toll on our physical, mental and emotional health. However, reading the various reports in the media on Vitamin D Deficiency being one of the causes for susceptibility to Covid-19 and raised concerns on the levels of mental health issues including depression, the comments from readers who are experiencing lack of energy and focus, I began to see some parallels to SAD, but six months ahead of schedule. You can find more about SAD in Part One

Regular visitors will have read my previous posts on Vitamin D but as one of the key nutrients for the efficiency of our immune system, I will keep banging this particular drum.

First a reminder if you missed the first post in this series of the symptoms of Seasonal Affective Disorder.

  • Depression
  • Anxiety
  • Inability to concentrate
  • Unexplained weight gain and loss
  • Slow growth in children,
  • Overeating of carbohydrates and sugars
  • Insomnia
  • Increased infections.

In my recent series Project 101 – Resilience I shared some of the recent research into the nutrient’s connection to the current pandemic.

There have been a number of risk factors identified that put certain groups of the population at a higher risk of a critical outcome from being infected with Covid- 19 – one of these is a deficiency of Vitamin D which is also a key nutrient in preventing SAD.

It was initially thought to be more common in those living in the Northern Hemisphere. However, there is also evidence that shows that middle-aged women in countries such as Greece and Italy also suffer from Vitamin D deficiency, largely due to the fact that they tend to cover up and avoid the sunshine. Many countries now fortify dairy products and other foods and that does appear to help the deficiency status of the population.

There have been a number of studies to determine if in fact having sufficient Vitamin D levels offers protection or minimises the severity of Covid-19, and this is obviously going to be ongoing and interesting to follow.

Researchers from the U.K. evaluated the average vitamin D levels and the number of COVID-19 cases, as well as the death rates, across 20 European countries. Countries with low average vitamin D blood levels in the population had higher numbers of COVID-19 cases and deaths, says study leader Petre Cristian Ilie, MD, PhD, research and innovation director at the Queen Elizabeth Hospital Foundation Trust in King’s Lynn, U.K.: Web MD

Vitamin D levels appear to play role in COVID-19 mortality rates: Patients with severe deficiency are twice as likely to experience major complications : Science Daily May 7th 2020

Researchers analyzed patient data from 10 countries. The team found a correlation between low vitamin D levels and hyperactive immune systems. Vitamin D strengthens innate immunity and prevents overactive immune responses. The finding could explain several mysteries, including why children are unlikely to die from COVID-19.

How Vitamin D works with our immune system.

Vitamin D is a bit like a health and safety consultant, constantly on the look out for areas that are unbalanced in the structure of our body and operating systems. I will look at the structure and bone density in other posts, but I want to share why the vitamin is being identified as playing a vital role in the strength of our immune system and in particular respiratory infections and auto-immune diseases such as arthritis. You can read more about the Immune System and how it works

Our white blood cells have receptors and activating enzymes for Vitamin D on their surface. It is a difficult role managing all the complexities involved in maintaining an efficient immune system without upsetting the balance… too much interference results in the immune system becoming overactive and attacking the cells of the body resulting in autoimmune diseases such as arthritis.. Too little interference is as bad, because dampening the immune system’s responses, leads to frequent infections.

Both these scenarios can occur if there is insufficient Vitamin D absorbed or ingested by the body, and whilst reduced levels of the vitamin do not cause an autoimmune disease, it can make matters worse.

Low levels of Vitamin D were identified in resulting in frequent colds and flu ten years ago, and with the pandemic, this line of research is going to be more closely monitored.

Supplementation Pharmacy News

In 2017, a large analyses of prospective clinical trials showed that taking vitamin D reduces the odds of developing a respiratory infection by approximately 42% in people with low baseline levels of 25-hydroxyvitamin D; below 25 ng/mL.3

The analysis suggests that taking vitamin D daily or weekly was more effective than larger doses taken in single or monthly boluses. The most common daily dose used was vitamin D3 300-4,000 IU.

N.B. I take 3000 IU daily during the months October to May and have a break if I have sufficient sunshine during the warmer months.

How do we get sufficient Vitamin D?

Whilst we are designed to produce our own Vitamin D from the interaction of sunlight on our skin,  there two forms of the vitamin found in foods are D2 (ergocalciferol) is the one activated by sunlight in the plants that we eat and D3 (cholecalciferol) is found in animal foods. D3 is the one that is most commonly used in supplementation usually in combination with calcium as it is the most biologically usable and effective for humans.

The link to cholesterol

When sunlight hits the skin it reacts with the cholesterol in the cells.  Without cholesterol the production of Vitamin D would be impossible.

This does raise a question for me. I am very anti-statins unless it is essential as cholesterol is an essential element in many processes in the body. It would seem to me to be very short sighted to mass prescribe statins for over 50s, particularly in the Northern hemisphere, when that age group is likely to be deficient in Vitamin D.  You can read more about Cholesterol and its importance to the body: The Cholesterol Myth – Part One – and Statins the new research!

Plant source of Vitamin D2

It has been identified that Vitamin D2 that we source from plants is not absorbed as effectively by the body. This means that vegetarians and vegans need to make sure that they obtain sufficient sunshine and consider supplementation under the guidance of a qualified practitioner.

N.B. If you have a liver or kidney condition then you should not supplement without your doctor’s advice. When we take in Vitamin D from food or sunlight it firsts goes to the liver and gets converted to one form and then onto the kidney to be converted into another form before being active and usable. If you have a liver or kidney problem you will be unable to convert the vitamin and will need the already activated form on prescription from your doctor.

Vitamin D taken in excess can be toxic and you should not supplement regularly more than 1000 IU to 3000IU per day. The upper limit for safety has been set at 10,000 IU per day and if you are getting adequate sunlight provided vitamin D you should not need to supplement in summer months.

The recommended daily levels are confused as since 1997 when the original levels were set at between 200 and 600 IU more research has indicated our actual requirement to be higher. An IU represents 5 micrograms. Researchers now believe that we need a minimum intake of 1000 IU rising as we age to 3000 IU which is the dosage that I take October to May daily. And sometimes during our Irish summers!!

Most of what we require on a daily basis is produced in the skin by the action of sunlight and many of us who suffer from depression through the dark winter months are actually missing around 75% of our required daily dose, this represents over 2000IU of vitamin D for someone in their 70’s. Since sunshine for most of us in the Northern hemisphere is going to be in shorter supply over the next few months I will let you check out how to maximise your exposure to this power source by heading over to this post: Vitamin D Deficiency – Getting Sufficient – Sunshine and Food

Artificial Sunlight.

I do use a sun lamp in the winter if only to feel the warmth on my face and relax for 20 minutes. For some years now light boxes have been used by those suffering from SAD but you do need to take care when using as misuse can be a problem for people with eye conditions such as glaucoma. A good idea to have a word with your doctor if you have underlying health issues before using. Here is a list of the top 10 available on Amazon and a good idea to check out the reviews. Best Light Boxes

This is not a substitute for Vitamin D from sunshine as most light boxes do not stimulate the skin to produce Vitamin D unless they have a specific ultraviolet spectrum between a specific range. However, care needs to be taken  as there is a risk of skin cancer. Research is ongoing. Science Daily

Food sources of Vitamin D

Our ancestors mainly worked outside until the industrial revolution and activities such as farming, fishing and hunting meant that we were exposed to sunlight throughout the day depending on the latitude and altitude of our immediate vicinity.

Those not lucky enough to get adequate sunshine would have instinctively sought other sources of Vitamin D from food. In those days it was the intestines, livers, kidneys, skin and fat of the animals they caught as well as seafood, oily fish and insects. It is obvious from this list how many foods have disappeared from our plates in the last 100 years.

When was the last time that you ate liver, kidneys, the fat on your steak or the crispy skin on your chicken?

We certainly have been told not to eat most of these to preserve our health but ironically it means that we are also missing out on viable sources of Vitamin D.

This has limited the available food sources of the vitamins and some of them are rather inadequate anyway.

eggsAn egg contains approximately 124 IU with a 100g serving of herring or tinned salmon providing just over 400 IU. Dairy products such as milk contain the vitamin but an 8oz glass only contains 100 IU unless it has been fortified. You will find many more dairy products and also orange juice that is now fortified with Vitamin D. However, this does mean that packaged products such as cereals, come with other additives, including too much sugar.

  • Pork fat contains 2,800 IU per 100gms so start eating the crackling again
  • Herrings contain 680 IU,
  • Oysters contain 640 IU (would need a lot more than a dozen)
  • Sardines 500IU.
  • Mackeral 450 IU
  • Butter 56IU
  • Salmon contains 450 IU per 100gm
  • Tinned or fresh tuna 155 IU per 100gm are good sources of the vitamin and well worth including regularly in your diet.

Mushrooms that have been grown exposed to UV light have varying amounts of Vitamin D and you need to read the labels.. I buy some Irish ones that are slightly more expensive but have a reasonable level.

Cod liver oil

As children we were given spoonfuls of cod liver oil and thanks to that simple breakthrough in the early 1900’s we did not get rickets.

I do recommend that everyone take high quality supplement during the winter months, or if unable to be outside to take advantage of sunshine.. Apart from the Vitamin D you will also be supplying your body with an excellent source of Omega 3 Fatty Acids essential for a great many of our bodies functions. Cod liver oil also contains rich amounts of vitamin A and the whole package may help protect you against age related diseases.

Today if you cannot face a tablespoon of the oil, you can obtain high quality cod liver oil capsules. There are lots to choose from so I suggest you shop around to find the best quality you can.

As we get older our skin thins and we are less able to manufacture Vitamin D naturally, which is when supplementation is really quite important..

Added to the current restrictions during shielding restrictions, this has become even more of an issue.

It is a good idea to take not only cod liver oil but also an additional supplement of calcium, magnesium and Vitamin D. This is important for both men and women to maintain the correct Acid/alkaline balance and also to balance hormone levels during midlife when breast and prostate cancer is more of a risk.

Next time, another essential element needed to ensure our mental and emotional health during the winter months… Tryptophan

©Sally Cronin – Just Food for Health – 1998 – 2020

I am a qualified nutritional therapist with twenty-two years experience working with clients in Ireland and the UK as well as being a health consultant on radio in Spain. Although I write a lot of fiction, I actually wrote my first two books on health, the first one, Size Matters, a weight loss programme 20 years ago, based on my own weight loss of 154lbs. My first clinic was in Ireland, the Cronin Diet Advisory Centre and my second book, Just Food for Health was written as my client’s workbook. Since then I have written a men’s health manual, and anti-aging programme, articles for magazines and posts here on Smorgasbord.

If you would like to browse my health books and fiction you can find them here: My books and reviews 2020

Your feedback is always welcome and if you do find that following any of the programmes that I have shared are beneficial then it would be great to hear about it.. you can email me on


33 thoughts on “Smorgasbord Health Column – UnSeasonal Affective Disorder – The Missing Link – Vitamin D by Sally Cronin

  1. I read somewhere (sorry, can’t remember where) that vitamin D deficiency is becoming a problem in the Middle East where people, especially women, cover up to avoid the sun (and of course for cultural reasons).
    Thank you for this post.

    Liked by 2 people

  2. This is such an important article, Sally. I’ve been taking a Vit D and Ca tablet for several years now, but will also try to have more of those delicious foods you suggest. In Australia we’re taught to use suncream and avoid the sun, so easy to get low in Vit D. Toni x

    Liked by 1 person

    • I have little doubt that Vitamin D has contributed to the severity of symptoms and the ability to patients to recover. There is plenty of sunshine in South Africa that is true as there is in the southern European countries but it is a question of exposure to that sunshine. I know that when we lived in Spain our friends might have exposure to the sun at the weekends during sports or if they used the communal pool, but many covered up or wore lots of high factor suncream. I am sure that the research currently being carried out on patients’ blood will look at a number of elements.. Amount of sunshine available, time exposed regularly to sun, diet which includes Vitamin D rich foods, rates of other infections etc. From a nutritional perspective working with clients over an extended period of time even though it was between 1998 and 2010, I was able to identify a difference in general health and frequency of infections following supplementation of Vitamin D3 and also recommended 40 minutes a day in sunlight early morning and late afternoon. I expect there will be a great many more answers in the next few months and that may be an area that we can all improve upon ourselves rather than relying solely on a vaccine…hugsxx

      Liked by 1 person

  3. I note the warning about VitD supplements if there are kidney problems – at the moment I do, thanks to the chemo so I guess I’ll have to try to get as much as possible from food. Luckily, I do like almost all the foods you listed (apart from kidneys, though love liver).

    Liked by 1 person

  4. Great article. Sunshine is so important – Maria Montessori insisted her charges get 20 min outside everyday for health. She was right., People have started warning too much sun screen is now causing unexpected problems. Common sense and moderation is a pretty good idea…along with real food for nutrition. I remember the old relatives talking about cod liver oil – maybe something to revive.

    Liked by 1 person

  5. I appreciate your great info Sal.I found it interesting what you said about statins lowering cholesterol too much making it bad for Vitamin D absorption. Again I learned something new about people with liver conditions can’t convert Vit D? Nobody ever told us that when I have to list G’s drugs at doctor visits? Even Dr. B? Now I’ll be on him for the ‘special converted? version’, I’d never heard of that. I think a sun lamp is definitely in order here, lol. Thanks for the info. ❤ xx

    Liked by 1 person

  6. Pingback: Smorgasbord Blog Magazine Weekly Round up 18th – 24th October 2020 – Streisand, Seasonal Affective Disorder, War Poets, Authors, Books, Reviews and Funnies | Smorgasbord Blog Magazine

  7. Pingback: Sharing: Smorgasbord Health - #VitaminD and #Covid19 - #Healthy

  8. This is an important article, Sally! My daughter lives in Oregon and her doctor recommended vitamin D to her. When the sun comes out, she makes sure to have the kids out. They go to the beaches often to get some sun. Even though one-third of the year is rainy, they try to catch the sun intentionally.
    I get enough sun in California but I’m taking D3 in the liquid form recommended by the doctor. My daughter would take D2 because she is vegetarian. Artificial sunlight is interesting. I’ll check it out and recommend it to my daughter.

    Liked by 1 person

I would be delighted to receive your feedback (by commenting, you agree to Wordpress collecting your name, email address and URL) Thanks Sally

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