6 causes of vitamin D deficiency
Given that vitamin D is known to very good for the immune system and has received much attention for this very fact, we can be left wondering if we are getting enough of this important nutrient. Here I explore 6 common causes of vitamin D deficiency, including:
- Insufficient sun exposure
- Low food sources as a result of dietary requirements
- Poor digestion
- Darker skin
- A struggling liver
- Being overweight
Throughout this blog I go into these themes in more detail, explaining how they could be affecting your vitamin D uptake and retention, and how best to protect it in a bid to support your immune system and overall health.
1. Insufficient sun exposure
We know that we get the majority of our vitamin D from the sun but, in recent years, with there being more of a focus being on sensible sun exposure, we might wonder how we're able to achieve a happy medium.
Crucially, we are only able to manufacture vitamin D at certain times of the year (April through to October in the UK) and at certain times of the day (when the sun is higher in the sky, approximately 11am-2pm). So, it's during these peak times we should consider ensuring we prioritise some outdoors time.
Best approach:
If you're hoping to strike a sensible balance between getting enough vitamin D whilst looking after your skin, then the advice is as follows:
- Aim to have short periods of time daily with your face, forearms or lower legs showing during the spring and summer months. This should be in the middle of the day.
- Don't be tempted to drown your skin in high factor sun cream, this may only be required if you are going to be in the sun for longer periods of time.
- It's not known exactly how much time is needed in the sun for each individual to make enough vitamin D to meet the body's requirements, as this varies depending on skin tone. But on average, this is recommended to be from as little as 15 minutes daily.
Find out more on my self-care video on this topic, below:
My Self-Care Tip: Sensible sun exposure to maximise your vitamin D production
Here I explain how to achieve a healthy balance of sun exposure for vitamin D production whilst also protecting your skin from sun damage.
2. Low food sources as a result of dietary requirements
Whilst for most nutrients, diet is the main route for getting sufficient amounts, when it comes to vitamin D, dietary sources are a little more limited. However, vitamin D does still exist in limited amounts in oily fish, eggs, mushrooms and fortified foods, such as cereals.
However, if you are vegetarian or vegan, your options for getting enough through your diet may be even more limited.
Best approach:
Include as many healthy vitamin D food sources in your diet as you can and do so on a regular basis. But, since most of us don't have the sun to help top up our intake for most of the year, an additional supplement is also recommended, especially during the winter months.
Remember, vitamin D is crucial for supporting and modulating our immune system so, especially during the winter when cold and flu bugs are at an all-time high, we really want to ensure we're keeping up our vitamin D intake.
Luckily, our Immune Support contains a healthy 200IU of vitamin D which is perfect for topping up your stores daily.
A.Vogel Immune Support Tablets with Vitamin D, Vitamin C and Zinc, 30 tablets
3. Poor digestion
When it comes to any nutrient deficiency, digestive ability is nearly always a potential contributing factor which, unfortunately, is quite commonly overlooked.
When it comes to fat-soluble nutrients such as vitamin D, firstly, we need to consume them alongside some healthy fats in our diet to give us the best chance of absorbing them, but that's only the first step – next, it's over to your digestion.
Fats and their counterparts start to become dismantled in the stomach, however, the release of digestive enzymes such as pancreatic lipase from the pancreas and bile from the gall bladder are the key steps for enabling efficient fat absorption in the first section of our small intestine.
Best approach:
Symptoms such as acid reflux, indigestion or bloating after meals could suggest that your digestion isn't in tip-top condition. If you worry that your digestion could be hindering the absorption of key nutrients from your diet then you might want to pay this some attention.
Bitter herbs such as Yarrow have been used traditionally to help step-up digestive power and options such as dandelion may assist with fat-absorption processes more specifically.
4. Dark skin
It's possible that the colour of your skin could also have an impact on how much vitamin D you're able to utilise from the sun. Melanin, which causes skin pigmentation, unfortunately, lowers the skin's ability to make vitamin D in response to sunlight exposure.
Best approach:
People with darker skin tones may need to spend a little longer in the sun, to help guarantee the manufacture of vitamin D.
Also, if you feel your body's production of vitamin D from sunlight exposure isn't adequate, you may need to step up in some of the other areas we've mentioned throughout this blog (which can be controlled), such as diet, supplement use or supporting your digestion.
5. A struggling liver
Whilst liver health falls back under into the category of 'digestive power'; when it comes to vitamin D, liver function is of particular importance so it's definitely worth a mention in its own right.
After sun-light exposure has kick-started the process, vitamin D is firstly hydroxylated in the liver into 25-hydroxyvitamin D. This, therefore, is a key step before the kidneys convert it further into its active form. This process in the kidneys is also influenced by the parathyroid hormone which is also a nice reminder of the part our endocrine glands have to play.
This whole process also highlights the interconnectedness of all the endocrine glands, as technically vitamin D is considered a pro-hormone.
Best approach:
Remember that a number of lifestyle habits can put pressure on your liver. However, on the plus, it's a very resilient organ and any positive changes you make in these areas can make all the difference.
Reducing your intake of medications (where appropriate), alcohol and caffeine, plus increasing water, green tea and cruciferous veggies – which your liver love - are habits, to name a few, which can help to keep things ticking over nicely.
6. Being overweight
New research is giving us a better idea of why being overweight could affect your nutrient uptake and retention.
Firstly, although the complicated modes of action aren't well understood, it seems that being overweight could mean that you struggle to absorb sufficient nutrients from your food. Next, being overweight or obese means that you risk excreting more of the nutrients you'd ideally like to hang on to – in a similar way that stress drains your body of nutrients, it seems. Plus, your adipose (fat) tissue may actually seize some of the vital nutrients you really need and it seems this process is particularly true for vitamin D, as shown in research.1
Finally, being bigger in stature, plus the additional inflammatory processes that being overweight or obese creates, means that we are likely to have a larger vitamin D requirement to start with.
Best approach:
Whilst the obvious approach is to work on achieving a healthier body weight, we fully appreciate this is often easier said than done and there are a lot of different factors involved to help achieve this. Again, a common theme, as always, I'd like to remind you of is that 'every little helps.' Even small steps in the right direction for long-lasting change can be very powerful.
Also, when it comes to vitamin D, I hope some of the other points throughout this blog help, including taking a good quality supplement if you think you could benefit from an extra dose.
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Article References
1. https://www.sciencedirect.com/science/article/pii/S0735109720361131b
Product references
1. https://www.ncbi.nlm.nih.gov/pmc/articles/PMC6098779/
2. https://www.sciencedirect.com/science/article/abs/pii/S0308814608010868
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