Are You Vitamin D Deficient? Tired, Drained, Flat?

by Jodie Leave a Comment

As a fitness instructor I encounter a whole host of issues that prevent people from exercising at worst and make exercise hard for them at best. We call these barriers to exercise but in truth they are blockers to our enjoyment of life in general – they are not necessarily exercise specific.

Now I am a qualified level 3 personal trainer and I have done an immense amount of research around these issues so that I can enhance the wellbeing of my clients. That said, for anything that I suggest in this series of blogs you will need a medical professional to confirm it. Some of these issues are easy to spot and receive treatment for but others are more complex and we will explore why that is.

So the first in this short series of blogs covers vitamin D deficiency. From a purely subjective and personal point of view I would probably label this one a pandemic. It affects a tremendous amount of people in the UK and I know of five clients as well as myself that take vitamin D regularly to avoid unwanted symptoms even a mild deficiency can produce.

Another great article with tons of research just completed which i very relevant to this blog: – do check it out!

So what does vitamin D do?

The most natural source of vitamin D synthesis is via exposure to sunlight. Technically it is more characteristic of a hormone than a vitamin because most mammals can receive their required levels through sun exposure. Equally you can digest vitamin D as part of your diet by eating:


  • Fortified cereals
  • Flour products
  • Some fruit juices and fruit juice drinks
  • Milk


Essentially what you are looking for are foods that have been fortified with vitamin D by manufacturers because it is not a common natural ingredient in food. The most likely way of taking enough vitamin D is via supplements as it is difficult to recommend exposure to sun as that could increase chances of skin cancer and isn’t always feasible for people with full time jobs.

Vitamin D then is made by the body and plays a key role in aiding the absorption of magnesium, phosphate, calcium, and zinc.

Vitamin D is believed, though studies and sound evidence gathering is still underway, to be used by the body to:


  • Increase your immunity against viral infection
  • Increase bone mineral density to help prevent reduced bone density (osteoporosis) or bone fractures
  • Essential for bone remodelling
  • Assist muscle function
  • Aid a strong cardiovascular system (healthy heart and circulation)
  • Contribute to a healthy respiratory system (healthy lungs and airways)
  • Help with brain development and focus (source)


How do you know if you are getting enough of it?

When I encounter people with fatigue during class, circles under their eyes, a pale complexion and I think they are capable of more then I start asking questions. Generally I am asking questions to get them starting to think about their health and their lifestyle. I ask them:


  • Did you get enough sleep last night?
  • You feeling alright or a bit tired? Bad day?
  • Have you ever suffered with an iron or B-complex deficiency?
  • Do you feel this a lot or just now and then


Depending on those answers I will either put it down to a bad day or a lack of sleep the night before or I will push them to go and get checked out. When I see people coming regularly and constantly hitting a brick wall I suspect vitamin D deficiency these days. I have seen it a lot. Someone is working as hard as they can and look absolutely shattered by the end of class but their work rate isn’t in line with others. Based on their age, ability and how long they have been coming I would expect more progress. They generally lack speed and look as though every single movement is a battle. They also usually struggle to lose weight if that is their target.

The most common symptoms people exhibit are:


  • Muscle weakness
  • Unexplained fatigue
  • Difficulty thinking clearly or concentrating


I would tell anybody that dips in energy during the day or finds exercise a chore that gives very little back, to go and see a doctor. Deficiencies are very common due to poor diets, stressful and hectic lifestyles and just a lack of awareness of what your body processes need for you to fire optimally. When you train you put greater demands on your body. If you are asking more of it and were already running low on a vitamin or mineral then your body is probably telling you but you are ignoring the signs.

I take zinc and magnesium, vitamin D and B-complex because my rigorous training has exposed these areas as needing supplementation. I knew there was an issue because my energy was crashing mid afternoon, I was feeling dizzy and faint at times and my mood peaked and troughed fairly frequently. I found what I needed based on my personal situation but everyone is different. There is some trial and error and a lot of research required but once you identify the potential issues you have the knowledge you need to take it to your GP. That will help them make the right decision of ordering a full spectrum of blood tests and finding what you are lacking.

In July 2016, Public Health England recommended that everyone consider taking a daily supplement containing 10 µg of vitamin D during autumn and winter because of inadequate sunlight for vitamin D synthesis. (source)

Research is being done into vitamin D as I write this. There could be more to uncover yet but based on my experience with clients I am a big believer in vitamin D supplementation. I will go into a case study to highlight my experience below.

How can you get a diagnosis?

It is important to go to your GP and get blood tests done. This will enable the NHS to supplement you correctly. You can take too much Vitamin D but the current max limit for daily intake lies at 80ug and most high concentration supplements are 25ug at most. So even with substantial Vitamin D intake through your diet you will still be very short of that maximum. But you should always check with your doctor before taking any supplements. There are different dosages for different ages and depending on where your levels are you could need a small or larger dose each day!

A deficiency of any kind needs diagnosing by a doctor. You may find that you can enhance your diet to get what you need. That approach is just rare with vitamin D because the foods that contain it are unnaturally fortified with it.

How will regular vitamin D change my lifestyle?

It could reduce fatigue and make you more energised during training sessions. It could also transform your training sessions, lift your mood and change your life. It depends on where your levels were before you started taking vitamin D.

Natalie Randall is a long standing client of mine and has struggled to get the most out of her workouts for years. I was constantly telling her to see an osteopath or chiro (big believer in alignment correction for pain resolution) and go and get a full blood works done.


She looked half asleep when she finished class. She would stare into space, struggle to maintain intensity and she had a lot of weaknesses that were preventing her from exercising aggressively. On top of that she was not losing any weight, despite doing three classes a week and sticking to a healthy diet.

After months of nagging she got a doctors appointment and then went in for her blood test. They found her vitamin D levels to be 18 which is extremely low. Natalie was prescribed 20,000 units a week which is clearly a very high dose to remedy the problem.

So Natalie started taking vitamin D tablets and then impatiently waited for them to make a difference. She told me each week that she had expected them to work by now, still no weight lost and she was still tired.

And then something changed. She describes it as “a switch had been flicked” and her energy levels shot up. Her effort levels shot up in class. She still looked alert and happy at the end (we have often done interval training straight after class) and she was losing weight for the first time in forever! It should be noted that Natalie also went to an Osteopath who found out her pelvis was out of line. The Osteo put it back in which prevented the spinal curving and also cured Natalie’s shin splints!

So, if you are feeling down in the dumps, struggling to lose weight, finding yourself lacking energy during the day. Then get yourself to a doctor!

We often put these issues down to stress, an unhealthy diet or illness but the fact is this is negatively impacting your life! You can soldier on and hope you get better but if you are deficient in vitamin D then chances are that day will never come (unless you spend a couple of weeks on holiday in the sun!).

Look after yourself and check out the blogs to follow on shin splints, anxiety, shoulder injuries and back pain.

JodieAre You Vitamin D Deficient? Tired, Drained, Flat?