Moving into autumn, with less sunlight, it’s the perfect time to talk about vitamin D and its importance for our health and vitality. In this blog, we’ll explore why this vitamin (actually, it’s a hormone!) is so essential, how to recognise if your levels might be low, who should consider getting tested, and of course, how to boost your levels.

Why Vitamin D Matters in Midlife

Vitamin D is often called the “sunshine vitamin” because our bodies produce it when exposed to sunlight. However, as we age, several factors can limit our ability to get enough of this vital nutrient. Reduced skin synthesis, more time spent indoors, and lifestyle changes all contribute to vitamin D deficiency, particularly in midlife. These deficiencies can have significant consequences, especially when hormonal shifts and declining bone density become prominent concerns.

Research shows that people with low vitamin D levels are 11 times more likely to experience depression, and there’s evidence that it may even help slow the progression of dementia and Alzheimer’s disease.

The Role of Vitamin D in the Body

Vitamin D supports several essential functions, particularly in midlife. Here’s how it helps:

1. Bone Health and Calcium Absorption: Vitamin D is critical for calcium absorption, which maintains bone density. With age, bone loss accelerates, increasing the risk of osteoporosis. Ensuring adequate vitamin D helps maintain strong bones.
2. Immune Function: As we age, our immune defences weaken. Vitamin D plays a vital role in modulating the immune response, helping the body fend off infections, reduce inflammation, and potentially lower the risk of autoimmune conditions.
3. Hormonal Balance: Midlife brings hormonal fluctuations, especially for women. Vitamin D helps regulate hormone production, including serotonin, which affects mood. It’s been linked to improved mood and a reduction in depression symptoms, particularly in the darker winter months.
4. Cardiovascular Health: Growing evidence suggests vitamin D influences heart health by regulating blood pressure, reducing inflammation, and promoting circulation. As cardiovascular risk increases with age, vitamin D plays an important role in heart health.

Why You Might Have Low Vitamin D

Several factors can contribute to low vitamin D levels, particularly in midlife:

1. Lack of Sun Exposure: Spending too much time indoors, especially during autumn and winter, or wearing sunscreen regularly can limit your exposure to UVB rays, which are essential for vitamin D production in the skin.
2. Ageing: As we age, our skin becomes less efficient at synthesising vitamin D from sunlight, even with regular sun exposure.
3. Darker Skin: Higher levels of melanin in darker skin reduce the ability to produce vitamin D from sunlight, putting people with darker skin at higher risk of deficiency, especially in northern climates.
4. Obesity: Vitamin D is stored in fat tissue, so those with higher body fat may have lower circulating levels as it becomes trapped in fat cells.
5. Dietary Insufficiency: A diet low in vitamin D-rich foods (like oily fish, egg yolks, and fortified dairy) can contribute to insufficient intake.
6. Gut Health Issues: Conditions like coeliac disease, Crohn’s disease, or chronic inflammation can affect vitamin D absorption.
7. Medications: Certain medications impair vitamin D absorption and conversion.
8. Kidney or Liver Disease: Impaired kidney or liver function can reduce the conversion of vitamin D into its active form.
9. Stress: The stress hormone cortisol may reduce vitamin D uptake in the body.

Signs of Vitamin D Deficiency

Recognising the signs of vitamin D deficiency is important to address the issue early. Here are some key symptoms that may indicate low levels:

1. Fatigue: Persistent tiredness or lack of energy, even with enough rest.
2. Bone Pain and Muscle Weakness: Aching bones, joint discomfort, or muscle weakness, which can often be mistaken for general midlife discomfort.
3. Frequent Illness: Low vitamin D levels may compromise your immune system, leading to more frequent infections.
4. Low Mood or Depression: Studies link low vitamin D levels with mood disorders like depression, especially in the winter.
5. Slow Wound Healing: Cuts or wounds taking longer than usual to heal could be a sign of low vitamin D.
6. Hair Loss: Severe deficiency has been linked to hair thinning or loss, especially in women.
7. Unexplained Weight Gain: Low vitamin D levels may contribute to weight gain or difficulty losing weight, as it plays a role in regulating fat metabolism.

Optimal Vitamin D Levels

The NHS recommends that adults aim for a serum level of 50 nmol/L or higher. However, many experts (myself included) suggest that an optimal range is 75-150 nmol/L. Levels below this could be insufficient, especially if you’re experiencing any symptoms mentioned above.

Testing Your Vitamin D Levels

It’s important to understand your individual vitamin D needs, and testing is the most effective way to determine whether you’re deficient or at an optimal level. You can request a vitamin D blood test through your GP or opt for a private testing kit. The test is called the 25-hydroxy vitamin D test (25-OH vitamin D test or Calcidiol 25-hydroxycholecalciferol test), and it measures how much vitamin D is in your body.

In my experience working with clients, many are surprised to discover they’re low in vitamin D, even if they’re eating plenty of oily fish and spending time outdoors during the summer. They don’t always connect the dots between their symptoms—like fatigue, low mood, or unexplained weight gain—and their vitamin D levels. Getting a simple test can quickly shed light on what’s going on, and from there, we can take action to get their levels back up, helping them feel like themselves again—often faster than they expect.

Getting the Right Support

If you’re nervous about asking your GP or just curious about your levels, private home-testing kits are available for as little as £39. You’ll receive guidance on how much to supplement safely based on your results. If you’re unsure or want more information, just hit reply, and I’d be happy to guide you.

If your test shows very low levels, you’ll likely need an intense supplementation period (4-6 weeks) and retesting to see the improvement. Although it’s rare, too much vitamin D can lead to toxicity, so always test before supplementing.

How to Boost Your Vitamin D Levels

There are three main sources of vitamin D: sunlight, food, and supplements.

1. Sunlight: Your skin produces vitamin D when exposed to UVB rays. However, in the UK and northern Europe, sunlight is often insufficient, particularly in the winter.
2. Food Sources: Fatty fish like salmon, mackerel, trout, and sardines, as well as egg yolks and liver, provide some vitamin D. Some fortified foods (e.g., cereals, margarine, yoghurts) also contain vitamin D, but these are often fortified with the less effective D2 form, not the natural D3.
3. Supplements: The NHS recommends 10 micrograms (400 IU) daily during autumn and winter. However, if you’re deficient, higher doses may be required, so get your blood levels tested first to determine your needs. Always consult with a healthcare professional or nutritional therapist before starting new supplements.

Final Thoughts: Take Control of Your Health in Midlife

Midlife can be a time of great change, but it’s also an opportunity to prioritise your health and wellbeing. Vitamin D is just one component of a larger picture, but it plays a crucial role in supporting strong bones, balanced hormones, a healthy immune system, and overall vitality.

Making sure you’re getting enough of this essential nutrient can help you feel more energetic, resilient, and ready to tackle whatever comes next in life.