Book your free Health Review call with me today - Find out more

Why you need Vitamin D in the Winter

How to know if you are vitamin D deficient@Nutrition_with_Lillia

There’s a lot to like about winter. I LOVE snuggling down with a book and cup of tea and watching the colour of the tree leaves changing in the woods, whilst walking the dog, on a crisp Sunday morning.

I won’t list the things I don’t like about winter, but no.1 is catching a cold/flu, and feeling a bit blue come January.

So, why is so much of that down to your vitamin D levels (sometimes called the ‘sunshine vitamin’ hence a lack of it in winter)? Vitamin D id vital for life, and if you don’t know your levels, is it essential you get yourself tested.

So how can you tell if your Vitamin D might be a bit low?
Who should get tested?
And where can you get this test done?

(I’m going to let you know what to say to your doctor to get this done free of charge). I’m also going to let you know how to boost your levels naturally through food but also explain that, food sources alone will NEVER give you enough vitamin D in winter.

Vitamin D is a superstar vitamin. More correctly, it’s actually a hormone. Low levels are bad news for your health and is linked to: cancer, osteoporosis, rickets in children, asthma, tuberculosis, multiple sclerosis, all autoimmune diseases, heart disease, diabetes and dental problems.


  1. Sun cream. Your body makes vitamin D after contact with the sun’s UV rays but, when the skin is covered up or sun cream is used the sun’s rays are blocked (note: we can only synthesise Vitamin D from the sun March-Oct in the Northern hemisphere).
  2. Age. As you get older, your body’s ability to turn sun rays into vitamin D decreases as the kidneys are less capable at turning it into the active form called calcitriol. Kidney or liver disease of any kind also means vitamin D is not converted to the active form.
  3. Tummy troubles. Problems with the digestive system of any kind: Diarrhoea, constipation, IBS, bloating etc mean the digestive tract does not absorb vitamin D from food as well as it could.
  4. Obesity (a BMI of 30+). Fat cells hoover up vitamin D, resulting is less available in your blood for use.
  5. Lack of sleep.  Just as you need sunlight to make vitamin D, you need sleep to actually use it.
  6. Stress. The presence of the stress hormone cortisol reduces vitamin D uptake, resulting in it not being used.
  7. Skin colour. The darker your skin, the less vitamin D you can make. This is due to the higher levels of melanin in your skin that protect against UV light. By blocking the sun’s rays, it also curbs the body’s ability to make the pre-cursor to the active vitamin D.
  8. Nightshift workers and anyone else who doesn’t spend much time in the sunlight, including children wearing sun cream all the time and babies. Quite simply, you need the sun on your skin.

Research shows you’re 11 times more likely to be depressed if you have low vitamin D levels.  
Vitamin D can also put the brakes on the progression of Alzheimer’s disease.


  1. Depression or anxiety (including mood changes or irritability)
  2. Bone softening (low bone density), fractures, osteoporosis
  3. Feeling tired all the time / fatigue / decreased performance
  4. Muscle cramps and weakness
  5. Joint pain (especially back and knees)
  6. Difficulty regulating your blood sugar levels / post lunch energy crash / 3pm sugar cravings
  7. Low immunity / frequent infections
  8. Slow wound healing
  9. Low calcium levels in the blood
  10. Unexplained weight gain

Symptoms like these are commonly overlooked because they don’t feel life threatening, and they’re often dismissed as normal, everyday aches and pains. But you don’t have to put up with these symptoms of ill health!

If any of the above resonates with you, then you need to get tested. You might find your GP will do this for you. My experience is that they are usually willing to do this blood test.

However, if your doctor won’t test, consider getting it checked out privately. It’s actually not expensive and correcting any deficiency could increase your enjoyment of your life.

The test is the 25-hydroxy vitamin D test (also known as the 25-OH vitamin D test or Calcidiol 25-hydroxycholecalciferol test) and it’s the most accurate way to measure how much vitamin D is in your body.

Your doctor will want to know that there is a valid reason for the test. Go back through the list of symptoms, write them down and go in strong at your appointment with this being the reason why you want to be tested.

If you’re the kind of person who doesn’t want to ask, feels uncomfortable asking or is just curious to know their levels, you can get a finger prick test done privately for £44. This can be done easily at home, then with the results you get guidance on how much to supplement safely. If this is you, and you want to know more please get I touch and I will let you know how.

If you do take a test and you’re very low, you will need an intense 4-6 weeks supplementation at a high dose and then re-testing to check your levels. It is possible to overdose on vitamin D (known as vitamin D toxicity). You’d have to be going some way to get there, but it is possible, which is why it is essential you know your levels before you start supplementation.

I know what you’re thinking. Here’s a few of those ‘yes, buts’ you have going on…

  • I already take a vitamin D supplement
  • I go out in the sun quite a bit
  • Wouldn’t my doctor ask to test me if they thought it were a problem?
  • I’m too busy to take time off to take a test.

I hear you. If you seriously have nothing wrong with you, if you didn’t identify with any of the symptoms in the list, then don’t bother. But if you did…

And here’s a cautionary tale… one of my clients [actually it’s me, this is true, but don’t tell anyone] enjoyed sunning herself in the garden this summer with no sun cream (except for her 2-week holiday in September). But despite it being mid-summer, my levels were 30% lower than what they should have been. The moral of this story is, be tested.


  • Get some sun. The recommended sunlight exposure is between 10-30 minutes a day with no sun cream during March-October.
  • Sit in front of a light box that supplies 10,000 lux of full-spectrum light for 30 minutes every morning. This is an especially good option for winter months and for night shift workers. Bit of a faff, but it’s an option.
  • Take a supplement. You can take a generic 1,000 IU dose as an adult (but not children without consulting your GP) BUT, if you’ve no idea what your blood levels are, how do you know how much you should be taking?
  • Eat naturally vitamin D-rich foods like oily fish (salmon, sardines, fresh tuna, trout, halibut, mackerel, etc.), high-quality cod-liver oil, egg yolks and liver. Do not be fooled into thinking the fortified foods are the same or have similar benefits. Fortified foods (like cereals, margarine, and some yoghurts) contain a synthetic version of the vitamin known as D2 (the natural form is D3). Research shows this is less effective at raising levels of vitamin D in the blood.

This summer I discovered a lovely little FREE app called D minder. It helps you track your levels of vitamin D by entering your test results and filling in details about supplementation and how often you go out in the sun. It will track your sun exposure and its impact on your vitamin D levels. It’s a little technical (and by that I mean just a little) so it’s probably only one for anyone with very low vitamin D or the geeks among you.

FREE GIFT: 6 hormone balancing meals

Discover your guide to healthy hormones

There are steps you can take today to regain your health and start balancing your hormones. Download my FREE ebook to start your journey back to feeling good again.


    Sign up and receive my FREE monthly female health tips, health hacks and recipes to help nourish your hormones.