After what felt like months of cold, damp weather, to see the sun and blue skies recently has really boosted my mood. I also noticed for the first time last weekend that my shadow was shorter than me – good news! This is a sign that the sun is strong enough, and high enough in the sky, for me to make vitamin D when I’m out and about.
Ironically, it may even have been low levels of vitamin D (aka the sunshine vitamin) that caused low mood during the long winter for some of us.
In this blog post I’m going take a close look at vitamin D and explore why you might not be making optimum amounts, or absorbing it from your food. We’ll look at how you can tell if you might have a deficiency and where you can get your levels tested. And finally, I’ll suggest ways to boost your levels naturally through food, if needed.
Why you really need vitamin D
Vitamin D is a superstar vitamin. More correctly, it’s actually a hormone. If levels are too low, it can have serious consequences for health. Low levels have been linked to cancer, osteoporosis, rickets in children, asthma, tuberculosis, Alzheimer’s disease, multiple sclerosis (and other autoimmune diseases), heart disease, depression, diabetes and dental problems.1,2
Why might your levels be low?
- Sun cream. Your body makes vitamin D after contact with the sun’s UV rays. However, as we’re, quite rightly, a nation of sun cream users, you might not be getting enough direct sun. Sun cream covers the skin, blocking the rays of sunlight from reaching the cells. Darker skins can reduce its synthesis in the same way. Higher levels of melanin in the skin protect against UV light and block the rays.
- Age. As you get older, your body becomes less efficient at turning the rays from the sun into vitamin D. Specifically, the kidneys become less able to turn it into its active form, calcitriol.
- Kidney or liver disease. Also reduces the conversion of that vitamin D to its active form so it has less effect in the body.
- Gut issues. Any sort of digestive health problems mean the digestive tract is not able to absorb vitamin D from food optimally.
- Overweight/obesity. Anyone with a BMI or body mass index of over 30 could find they have lower levels. Fat cells store a significant amount of vitamin D, so the body is unable to access it.
- Stress. The presence of the stress hormone cortisol reduces the uptake of vitamin D by receptors.
- Nightshift workers and anyone who doesn’t spend much time in the sunlight, or covers up when outside. Quite simply, you need the sun on your skin to make vitamin D.
10 signs you might have a vitamin D deficiency
- Depression or anxiety, including mood changes or irritability
- Low bone density or frequent fractures
- Feeling tired all the time or lacking in energy
- Muscle cramps and weakness
- Joint pain, especially of the back and knees
- Difficulty regulating blood sugar levels or experiencing a post lunch energy crash
- Low immunity – frequent colds and coughs
- Slow wound healing
- Low calcium levels in the blood
- Unexplained weight gain
It is easy to overlook symptoms like these because they don’t feel life threatening. They’re often dismissed as normal, everyday aches, pains and fatigue you have to deal with as part of life. But you don’t have to put up with them!
Who should get their levels tested?
If any of the above resonates with you, then it is worth getting your vitamin D levels tested. Vitamin D is a fat-soluble vitamin, and is stored in the body. It is therefore possible to have too much, known as vitamin D toxicity. For this reason it is essential you know your levels before you start taking any supplements.
The test is a 25-hydroxy vitamin D test (also known as the 25-OH vitamin D test or Calcidiol 25-hydroxycholecalciferol test). It’s the most accurate way to measure how much vitamin D is in your body.
If you are looking to have a test on the NHS, your doctor will want to know that there is a valid reason to do so. Look through the list of symptoms above and note down any that apply to you. Explain them to your GP as the reason that you want to be tested.
If your doctor won’t test, you feel uncomfortable asking, or you would just like to know your levels out of curiosity, you can get the test done privately. It is a relatively inexpensive test (in the region of £40) and is a finger prick test, so you can do it easily at home. Once you know your current levels, then you can be guided on how much to supplement safely. If this is you, and you would like to know more, just get in touch and we can discuss ordering a test for you.
If you do take a test and your levels are very low, you’ll need an intense 4-6 weeks supplementation at a high dose, followed by a re-test to see the impact it’s had.
How to increase your vitamin D levels
Once you know your levels, there are a few ways to increase your vitamin D levels…
- Get some sun. Recommended sunlight exposure is between 10 and 20 minutes a day with no sun cream. After this time, apply sun cream if you’re staying out any longer.
- If getting out in the sun is not an option, sit in front of a light box. Choose one that supplies 10,000 lux of full-spectrum light for 30 minutes every morning. This is an especially good option for winter months, or for night shift workers.
- Take a supplement. You can take a generic 1,000 IU dose as an adult but without knowing your levels to begin with, it’s hard to know exactly how much you should be taking. Please note that children must consult their GP before supplementing.
- Eat naturally vitamin D-rich foods. This includes oily fish (salmon, mackerel, anchovies, sardines, herrings etc.), high quality cod liver oil, egg yolks and liver. Unfortunately, fortified foods (cereals, margarine and some yoghurts) contain a version of the vitamin known as D2, rather than the natural form D3. Research shows that D2 is less effective at raising levels of vitamin D in the blood.3
1. Hossein-nezhad A. et al. Influence of vitamin D status and vitamin D3 supplementation on genome wide expression of white blood cells: a randomized double-blind clinical trial PLoS One. 2013
2. Mizwicki, M. et al. Genomic and Nongenomic Signaling Induced by 1α,25(OH)2-Vitamin D3 Promotes the Recovery of Amyloid-β Phagocytosis by Alzheimer’s Disease Macrophages Journal of Alzheimers Disease. 2012
3. Tripkovic, L. et al. Comparison of vitamin D2 and vitamin D3 supplementation in raising serum 25-hydroxyvitamin D status: a systematic review and meta-analysis The American Journal of Clinical Nutrition. 2012
Fat: the facts