Why Vitamin D Matters More Than Ever for Modern Health

Do you think you get enough from the sun? You don’t. This month it’s about the real depletion we’re all facing of vitamin D; and how it supports your body’s health plus how to take the right amount. I’m very passionate about this subject as I believe so many health concerns can be reduced or avoided with simply taking this vitamin! More and more Dr’s are taking to YouTube and social media to get this message across: vitamin D deficiency is exacerbating many of the chronic health patterns seen nowadays and in the worst-case scenario is a contributing factor in many cancers.

Even in a sunny Mediterranean environment, researchers have found that vitamin D deficiency and insufficiency are very common among Spanish adults (especially older individuals). You wear SPF? You’ll get zero. If you don’t spend around 30 minutes (without SPF) in the sun between 11 and 3pm (in a country further south) with all limbs exposed (every day of the year) you will not get the vitamin D you need. So, what is the chance of you getting enough when you live in the UK or this far north/south of the equator?

Vitamin D is so important it is THE ONLY vitamin that our bodies make (all the rest come from food). Vitamin D has now been reclassified as a hormone because of all the functions that it supports in the body. Vitamin D is THE CHEAPEST supplement you can buy (no wonder the giant ph*rma have put so much misinformation out there to put you off taking it; they can’t make money from it). Today you’ll gain insight into the most powerful vitamin you can take!

Why Vitamin D matters more than ever in modern health

As a student of Chinese Medicine and holistic health, I’ve seen firsthand how nutrient status affects people’s wellbeing: sleep quality, energy levels, hormonal balance, emotional resilience, and recovery from illness. Many clients also describe deep improvements after supporting their vitamin and mineral status — especially vitamin D, vitamin C, and magnesium, often alongside a high-quality multivitamin.

While we can get nutrients from food modern agriculture and environmental stresses mean that food quality is not what it used to be. Soil depletion, chemical fertilizers, pesticides, and long supply chains all reduce micronutrient density in plants and animals. Meaning many of us aren’t getting what we need from food alone.

I explore these major nutrients, why they matter, and how they function in the body; both from a Western biological perspective and in ways that resonate with my holistic health principles.

Vitamin D: It’s not bone health it’s health!

Vitamin D your sunshine vitamin created via photosynthesis in your skin, is mainly associated with bones and calcium metabolism. But research shows it does much more:

1. Calcium, Bones, and Muscle

Vitamin D enhances calcium absorption from the gut, supports bone mineralisation, and helps maintain muscle strength. After menopause, when oestrogen levels fall and bone density declines rapidly, this role is especially critical to prevent osteopenia and osteoporosis.

2. Immune Function & Systemic Health

Vitamin D interacts with immune cells and has a modulatory effect on inflammation — potentially reducing susceptibility to infections and regulating immune responses. While trials on infections and observational studies suggest associations between low vitamin D and higher risk of respiratory illness, cardiovascular events, and immune dysregulation.

3. Further health advantages

• Vitamin D receptors are present in tissues related to cardiovascular health, metabolism, respiratory function, immune function, and genitourinary health.

• From my personal perspective when I increased my dose of vitamin D dramatically it had a direct reduction on hot flushes that I recently started getting.

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A recent study specifically on postmenopausal women shows that low circulating vitamin D levels are linked to poor bone markers, lipid metabolism changes, and metabolic syndrome. Meaning osteoporosis and weight gain maybe reduced when levels of vitamin D are optimal.

Vitamin D is intimately tied to hormonal regulation, immune function, stress responses, inflammation markers and energy metabolism. Without listing diseases an imbalance in all of these areas allows major health conditions to manifest.

 Optimal Levels of Vitamin D and How Much to Take

The US Official dietary guidelines suggest 600–800 IU daily, and the NHS only 400 IU.  In functional and integrative medicine, the amount to take for optimal health is far larger and that suggests that official guidelines leave you well below the target for actual baseline health.  In fact, a study 10 years ago in the US showed that these minimal levels were too low and that we should be on 8-9000 IU a day! This information has only resurfaced recently and brought to light by the likes of Dr John Campbell (youtube.com/@Campbellteaching).

Read the study results here: A Statistical Error in the Estimation of the Recommended Dietary Allowance for Vitamin D

Dubious testing

Beware of rapid flow tests and NHS results. The former will just give you a valid ‘sufficient’ marker; and if less then you do need significant supplementation. For the NHS testing don’t take their word for it; ask the exact result. When you’re given the results, they will look like this:

25-hydroxyvitamin D (25(OH)D) levels in the 30–50 ng/mL range is just sufficient. For optimal health though you’re looking for 50-100ng/mL range. (source: Blood Labs – to reduce fatigue by Kate Knowler)

She recommends that just daily vitamin D maintenance is 3000 IU once you've reached optimal levels which could take 2-4 weeks of doses between 6-9000 IU.

In naturopathic practice, Dr. Charles Rouse (MD and naturopath) uses a functional dosing rule of 35 IU per pound of body weight — meaning a 140 lb person would take approximately 4,900 IU/day as a maintenance dose (35 × 140). This takes into account individual needs and baseline levels, not a one-size-fits-all low dose. 

Personal results:

Dr John Campbell tested and found that he was insufficient despite taking 10000 IU daily. I'm currently on 11000 IU daily (short term) and I have really felt the difference in energy levels and heat levels. Results differ widly per person and testing is incredibly helpful at titrating dosages and ensuring you're not over supplementing but also not deficient! You can get a test Dr John Campbell tested and found that he was insufficient despite taking 10000 IU daily. I'm currently on 11000 IU daily (short term) and I have really felt the difference in energy levels and heat levels. Results differ widly per person and testing is incredibly helpful to ensure you get your dosage correct to maintain an optimal level. You can get a test kit here.

In short – in taking the cheapest supplement on the market you can reduce the number of chest /colds/flu infections you have, significantly reduce the chances of osteoporosis, skin cancer, prostate cancer, breast cancer and many more chronic health issues linked to vitamin D deficiency.

💡 In Chinese medicine vitamin D supports yang (warmth), immune resilience, and constitutional strength — a combination of the energies of the Lungs and Kidneys known as the nourishing Zhen qi (true qi) which stabilises bodily systems that otherwise decline with age, stress, or deficiency.

Alongside vitamin D these are the magic minerals for health!

Magnesium: The “Relaxation Mineral”

Magnesium is a cofactor in more than 300 biochemical reactions, including those involved in muscle relaxation, nerve function, sleep regulation, and energy metabolism.

1. Sleep and Stress

Many people today are deficient in magnesium due to soil depletion and high stress. Supplementation with magnesium has been linked to improvements in sleep quality, reduced anxiety, and better muscle relaxation.

Emerging clinical and observational evidence supports magnesium’s role in improving vitamin D status, especially in postmenopausal women: supplementing magnesium increased vitamin D levels in women with deficiency.

This reinforces the idea that nutrients work synergistically — you can’t think about vitamin D without considering magnesium, zinc, and K2, for example.

2. Hormonal and Nervous System Support

While direct RCT evidence on magnesium for hot flashes is limited, magnesium’s calming, muscle-relaxing, and neuroregulatory effects make it a cornerstone nutrient for hormonal transition phases where sleep and thermoregulation are often disturbed.

In practice, many peri/menopausal individuals report improved sleep, less night waking, and reduced tension when using magnesium glycinate or citrate forms.

💡 From a Chinese medicine perspective, magnesium supports liver blood and yin fluids, which are central to sleep, emotions, and steady heat regulation.

Vitamin C: Antioxidant and Stress Buffer

Vitamin C is a powerful antioxidant that supports immunity, collagen formation, adrenal function, and general stress resilience.

1. Immune System & Tissue Support

Vitamin C is essential for white blood cell function and the health of skin and connective tissue, which can decline with age and stress. Arterial stiffness is reduced with vitamin C as it supports lubrication and elasticity of the connective tissues (i.e. collagen fascia and muscle fibres).

Unlike fat-soluble vitamin D, vitamin C is water-soluble, meaning excess is excreted – therefore it’s a great one to take at night as it can be absorbed and utilised. The higher dosing ones are Ascorbic Acid (and mine also has bioflavonoids in for cardio health). If you have a sensitive stomach then you can get whole fruit orange or the more gently Cherry one.

While not as deeply studied specifically for hot flushes, its role in adrenal support,  stress buffering and arterial flexibility makes it a valuable part of a broader nutrient strategy (and from my client observations does reduce hot  flushes).

Multivitamins: fill in the gaps  - synergistic support

A high-quality (i.e. plant-based for maximum absorption) multivitamin can help fill the mineral gaps. The collective trace minerals are so often overlooked and this is the supplement I always tend to remind people to add in. In a world with lower soil nutrient density and pervasive environmental stressors many are missing in the diet. Multivitamins provide:

• B vitamins for energy, mood, and nervous system function

• Trace minerals for hormone synthesis and metabolic support

• Co-factors that help vitamins D, C, and magnesium function optimally

Research reviews support the role of vitamins and minerals in maintaining overall health in midlife including bone health, metabolic balance, cognition, and cardiovascular resilience.

Think of it like an old-fashioned triangular tent – the tent pole alone can’t hold the tent up you need the guy ropes with the right tension – this is your multivitamin. Vitamin B12 in isolation of the B complex can’t do the whole job and then the trace minerals prop up the B Complex. If you’re taking a B12 injection only; support with the B complex in the multivitamin like the one I take you’ll reap the energetic benefits.

Click image to download my free guide to the ones I use

Supplementation is a practical, evidence-based bridge to support health and resilience when food alone isn’t enough. Alongside Shiatsu I ensure that you have a whole holistic health protocol for the month not just your treatment.

 

A Holistic Prescription: Integrating East and West

From a Shiatsu/Chinese medicine lens supplements help me and my clients when there are patterns of deficiency. I first came across this when treating perimenopausal women. Some would come for shiatsu weekly feeling the benefits but only for a day or so. I realised that something was needed to fill up these patterns of deficiency. In training for shiatsu, we are told we have ‘everything within us to help us’ and I stuck to this mantra for as long as I could; until I couldn’t anymore.

One day I was having this conversation with a client who had multiple health issues and she commented:’ that’s fine unless you don’t have the full tank to begin with’. This was a lightbulb moment for me – if we’re in such patterns of deficiency then we need to insert fuel into said tank!

The 3 avenues to replenish Qi are – Lung Qi and Spleen Qi feeding into an further supporting Kidney Qi (rejuvenation through proper resting). The one factor in this 3-part support system that is potentially weakened is Spleen Qi  - in simple terms the nutrients extracted from what we eat; and we know this is be severely impaired at this time.

With this thought I tried Magnesium the first of my supplements on this journey and it made a difference from night one. My sleep had been awful for a whole month and it was depressing me. Magnesium helped me sleep from the first night and that changed my opinion of supplements – yes overnight! I was eating bags of almonds for my Magnesium source (as well as other nutrition; I had a good diet). Then just one capsule of Magnesium gave me my sleep back.

Since on regular multivitamins and Vitamin C I don’t tend to get colds and during the Covid years I had me and my mum on high doses of vitamin C and D; but then you get lazy. I’d let slip on vitamin D over the last 3 years dropping in the summer because hey it was sunny – however…

Practical Guidelines for your supplement taking

Vitamin D

• Functional daily maintenance dosing idea: 35 IU per lb of body weight (Dr. Charles Rouse) — e.g., ~5,250 IU for a 150 lb person.

• Aim for serum levels around 50-100 ng/mL (individualised) for optimizing health.

• Pair with magnesium, vitamin K2, and a meal containing healthy fats.

• Vitamin D strengthens yang, supports qi, and nourishes Kidney and Spleen systems — the foundation of vitality.

  
  

Magnesium

• Common supplemental range: 300–500 mg/day, often at bedtime or split am/pm.

• Magnesium calms Liver qi, which is essential for sleep and emotional balance.

Vitamin C

• Around 1000 mg/day (or 200mg if fruit source), can double in times of stress and illness.

• Vitamin C supports protective qi and detoxification.

Multivitamin

• Daily, with minerals and co-factors to support overall balance. There are options of high or low iron ones. I use this one

• A multivitamin fills gaps and supports the body’s constitutional balance.

This complements bodywork, movement, stress reduction, and personalised nutrition.

Shiatsu and Supplements for optimal health

Supplements aren’t a shortcut they’re a supportive foundation when used alongside food, lifestyle, and holistic therapies. What I’ve learned from shiatsu clients mirrors broader research: when the body has the nutrients it needs, sleep improves, energy stabilises, stress abates, and hormonal shifts feel more manageable.

Taking these nutrients with intention and in the right amounts helps support your body’s innate ability to heal and balance itself.

These effects parallel a holistic health protocol where nutrients support qi, yin-yang balance, and overall vitality. Vitamin D is a hormone-defined compound that affects hundreds of genes and many biological systems, and could be your quickest, easiest and cheapest route to better health!

I hope today you've gained insight into why vitamin D matters more than ever in modern health?

As part of Shiatsu for Health I’m happy to suggest the vitamins and minerals that would support any depletions that appear as part of the treatment.

Always consult with a healthcare provider to confirm personalised dosage and testing.

About Andrea at Shiatsu Bodyworks Cheltenham

Andrea is a qualified zen shiatsu and chinese medicine practitioner with over 20 years immersed in holistic therapies and the energetics of mind and body. Based in Cheltenham, UK she offers in house clinic and online shiatsu sessions to help people with midlife health issues and also offers online consultations as she is a menopause specialist too.

Ready for a treatment? Book in here! 

Shiatsu ~ Gentle bodywork to help your body work better