Are you getting enough vitamin D? How to check and why it matters more than ever
A healthy diet simply isn’t enough
You’re already doing your best to manage your diet, perhaps trying to eat as cleanly and healthily as possible. But if you’re also navigating an autoimmune condition, like rheumatoid arthritis, lupus or multiple sclerosis, you know that it’s not always as simple as eating right. You may still feel drained, struggle with joint pain and find that your immune system is working against you.
What if there was a missing piece to the puzzle, something that could help you get a handle on your condition and improve your health? That missing link could just be vitamin D - a nutrient that plays a pivotal role in regulating immune function. Read on to find out how checking your levels could help transform how you feel.
The sunshine vitamin explained
Vitamin D, also known as the "sunshine vitamin," is not just about keeping your bones and teeth strong. Its role extends deep into your immune system, acting as a central controller that can make all the difference in how your body fights off illnesses, including autoimmune attacks. It’s actually more like a steroid hormone rather than a vitamin and together with its immune effects has significant influences on mood and depression, balancing blood sugar and heart health, it is believed to impact the function of over 2000 genes.. that’s a pretty big deal! [1]
Where do we get it from?
Sunlight: Sunlight is the primary source, but the reality is that many of us in the UK simply don’t get enough exposure, especially during the months October-March, when the sun is at the wrong angle.
Diet: Although certain foods like oily fish (salmon and sardines), egg yolks, mushrooms (if grown in sunlight) and fortified dairy products contain vitamin D, they only provide around 10% of our needs on average — not enough, especially if you're managing a chronic condition that increases your nutrient demands.
You can see how easy it is to become deficient!
Why don’t we get enough from food?
The average UK dietary intake is a paltry 124iu and 28iu in vegans (while the NHS recommends supplementing 400iu per day over winter). It’s almost impossible to get sufficient vitamin D solely from food. For those managing chronic conditions, this shortfall is even more significant because your body's requirements are higher and you need more support to keep inflammation in check.
The vital functions of vitamin D - a lifeline for autoimmune health
If you’re living with an autoimmune condition, you know how critical it is to find ways to calm your immune system and reduce inflammation. This is where vitamin D stands out. Research shows that vitamin D is not just a bone protector; it's a key player in immune system regulation, helping your body distinguish between real threats and its own tissues (the part that goes awry in autoimmune conditions).
Your body’s natural immune system controller
Guides the immune response - Vitamin D acts like a conductor in your immune system, enhancing natural immunity while calming excessive inflammatory responses that can worsen autoimmune conditions.
Reduces autoimmune activity - Studies have found that vitamin D helps prevent your immune system from mistakenly attacking your own tissues, reducing the risk and severity of flare-ups in conditions like lupus (SLE), rheumatoid arthritis (RA) and multiple sclerosis (MS).
Promotes antimicrobial defences - It increases the production of natural antimicrobial proteins that help your body fight off infections, which is essential if you’re already dealing with a compromised immune defence.
A recent study published in the BMJ showed a 22% reduction in new autoimmune disease diagnoses in those who supplemented 2000iu of vitamin D per day over 5 years. [2]
Vitamin D has also been shown to support MS by reducing the risk of relapses, while deficiency is linked to an increased risk of developing the disease. [3]
An overall health hero
Beyond its crucial role in immune regulation, vitamin D supports various systems in your body, influencing how you feel and function. If you've ever experienced lingering fatigue, difficulty concentrating at work, or even a persistent sense of low energy that makes getting through the day a challenge, low vitamin D levels could be a contributing factor.
Mood and mental well-being
One of the lesser-known but highly impactful roles of vitamin D is its effect on mood and mental health. It helps regulate the production of serotonin, often dubbed the “happy hormone” which directly affects your mood, sleep and stress levels. Low levels of vitamin D have been linked to increased rates of depression, anxiety and even seasonal affective disorder (SAD). So, if you're feeling persistently low or finding it hard to shake off that brain fog at work, boosting your vitamin D levels could make a significant difference in your mental clarity and mood.
Cardiovascular health
Vitamin D also plays a vital role in maintaining a healthy heart and circulatory system. It influences blood pressure regulation, supports the function of your arteries and optimal levels are associated with a reduced risk of heart disease.[4]
Bone and muscle strength
Most people know vitamin D for its role in bone health, but its impact on muscle function is just as important. If you've noticed unexplained muscle weakness, cramps or an increase in injuries, low vitamin D could be at play.
Hormonal balance and metabolism
Hormones like insulin, thyroid hormones and sex hormones, also rely on vitamin D to function properly. For example, vitamin D helps improve insulin sensitivity, leading to more stable blood sugar levels - a crucial factor if you're struggling with energy slumps or food cravings during the day.
Digestive health and gut integrity
Emerging research suggests that vitamin D also plays a role in gut health, promoting a healthy balance of gut bacteria and supporting the intestinal lining.[5] Since a healthy gut is linked to improved nutrient absorption and reduced inflammation, this is super important for those managing any kind of autoimmune condition. A well-functioning gut can lead to better digestion, less bloating and more sustained energy throughout your day.
Risk factors for low vitamin D
Certain factors can make you more susceptible to low vitamin D levels, increasing the risk of autoimmune flare-ups and complications. Take a moment to understand these so you can make targeted steps to improve your health.
Limited sun exposure: If you're often indoors due to work, fatigue or limited mobility, or you cover your skin with clothing you might not be getting enough sunlight to produce sufficient vitamin D.
Chronic inflammation: Autoimmune diseases increase your body's nutrient demands, meaning you need more vitamin D to help regulate the immune response.
Obesity: Vitamin D can get trapped in fat cells, making it less available to your body.
Age and skin tone: As we age, our skin’s ability to synthesise vitamin D decreases by around 50% and those with darker skin tones naturally produce less vitamin D from sunlight.
Medications: Particularly those such as corticosteroids (often prescribed in autoimmune cases), PPIs, metformin and bile acid sequestrants.
Digestive issues: For those suffering with IBD, or who have had gastric surgeries, gallbladder issues, coeliac disease or cystic fibrosis, absorption becomes more difficult.
Vegan/vegetarian diet: Food sources are more limited. Mushrooms contain a small amount but in a less available form (D2 is about 30% as potent as D3).
Nutrient deficiencies: Vitamin D relies on various synergistic nutrients to work to its full effect - vitamin A and magnesium.
Genetics: See below…
The genetics connection - why your DNA matters
One of the most overlooked factors in vitamin D deficiency, especially for those with autoimmune conditions, is your genetic makeup. Variations in specific genes can significantly impact how your body processes and utilises vitamin D, as well as other nutrients. If you have these genetic variants, standard vitamin D levels might not be enough to support your health, especially when managing an autoimmune condition. These are the two main genes impacting its function:
VDR (vitamin D receptor) gene - Variations in this gene can reduce your body’s ability to respond to vitamin D, impacting everything from bone health to immune regulation.
GC (group-specific component) gene - This gene plays a role in transporting vitamin D through your bloodstream. Certain variants affect how well vitamin D is carried to where it's needed in your body.
Nutrigenomics is a field examining the relationship between genetics, dietary nutrients and associated health impacts. As a Master Nutrigenomics Practitioner I interpret how your individual genetic variations impact your body’s ability to process vitamin D and other nutrients. We are all wonderfully unique! If clients have these variants I will support them to maintain higher levels of vitamin D.
A simple step towards better health … test
Testing your vitamin D levels doesn’t have to be complicated. You can easily do an at-home finger prick test that gives you a precise view of your current vitamin D status. For those with autoimmune conditions, knowing these levels could be a turning point in managing your health more effectively.
If you haven’t ever tested your levels or can’t remember the last time, then now is probably a good point to get it done.
What are the optimal levels?
While severe vitamin D deficiency is usually defined as levels below 25-30 nmol/L, many experts argue that anything below 50-75 nmol/L indicates a lack of sufficiency. Ideally, levels should be in the range of 75-150 nmol/L for most individuals, with the upper end of this range being where I aim to get my autoimmune clients or those with genetic variants, but this will vary individually. It’s always best to work with a health practitioner to determine your own optimal levels and needs.
Interestingly, research into the vitamin D levels of pastoral hunter-gatherer populations in Tanzania suggests they have average levels of 115 nmol/L, which might be a closer indication of what our bodies are naturally designed to maintain.[6]
Should you supplement?
In the UK the NHS advises supplementing 400iu (or 10mcg) per day between early October and late March. But, as noted earlier, this will be highly dependent on your individual levels and needs and nutrition professionals will generally be looking at amounts higher than this to optimise health.
Personalised support for your health journey
If this has got you curious about testing or digging deeper to see if you have any underlying genetic variants impacting vitamin D, I’m here to help. I work with clients to offer more than just a surface-level understanding of vitamin D, looking at the intricate relationship between your genetics and your nutrition to unlock your full potential. This approach is ideal for those who are serious about taking control of their health, especially when managing the complexities of autoimmune diseases.
This is not a standard, one-size-fits-all approach; it’s a tailored strategy based on your unique genetic blueprint, together with testing your current vitamin D levels. With my guidance, you’ll receive a 1:1 consultation, a personalised nutrition and supplement plan designed to optimise your vitamin D levels, help reduce inflammation and support your overall health.
In summary
Vitamin D’s impact on overall health and the immune system is crucial, particularly for those dealing with autoimmune conditions. But the true power lies in understanding how your genetics influences your response to vitamin D and your levels. I analyse these genetic factors and create a bespoke health strategy tailored to your unique needs.
Incorporating vitamin D into your wellness routine isn't just about addressing one health issue; it’s about enhancing your overall quality of life. When your vitamin D levels are optimised, you might notice more energy to tackle your to-do list, a brighter mood to handle stress at work and even a greater sense of well-being in your everyday life. Whether you're managing the complexities of an autoimmune condition or simply striving to feel your best, vitamin D is truly an overall health hero that can make a real difference in how you experience life.
Ready for more support?
Order your at-home vitamin D test today (book here), check your levels are optimised and receive a personalised nutrition and supplement plan tailored to your unique needs.
For a truly comprehensive approach, consider a full review, including DNA testing (book here), together with a bespoke 1:1 consultation, nutrition and supplement plan. With my specialist knowledge in nutrigenomics, we’ll unlock your genetic code and give you a whole new insight to empower you to manage your health more effectively.
References:
Wacker M. & Holiack M.F. (2013) ‘Vitamin D-effects on skeletal and extraskeletal health and the need for supplementation’, Nutrients https://www.ncbi.nlm.nih.gov/pmc/articles/PMC3571641/
Hahn, J. et al. (2022) ‘Vitamin D and marine omega 3 fatty acid supplementation and incident autoimmune disease: VITAL randomized controlled trial’, BMJ https://www.bmj.com/content/376/bmj-2021-066452
Sintzel, M.B. Rametta, M. & Reder, A.T. (2018) ‘Vitamin D and multiple sclerosis: a comprehensive review’, Neurology and Therapy https://www.ncbi.nlm.nih.gov/pmc/articles/pmid/29243029/
Wang, T.J. et al. (2008) ‘Vitamin D deficiency and risk of cardiovascular disease’, Circulation https://www.ahajournals.org/doi/full/10.1161/CIRCULATIONAHA.107.706127
Yamamoto, E.A. & Jørgensen, T.N. (2020) ‘Relationships between vitamin D, gut microbiome, and systemic autoimmunity’, Frontiers in immunology https://www.frontiersin.org/journals/immunology/articles/10.3389/fimmu.2019.03141/full?ref=tomecontroldesusalud.com
Luxwolda M.F. et al. (2012) ‘Traditionally living populations in East Africa have a mean serum 25-hydroxyvitamin D concentration of 115nmol/l’, British Journal of Nutrition https://pubmed.ncbi.nlm.nih.gov/22264449/