10-07-2025
The ‘quiet hero' 2p supplement that could help fight cancer and boost weight loss – plus 5 other health benefits
A SINGLE pill to fix all ailments sounds like the Holy Grail of medicine - and while it doesn't quite exist yet, the good news is one comes pretty close.
The supplement, best known for its crucial role in bone health, has been linked to a wide variety of other health
benefits
- from hay fever to weight loss and boosting your mood.
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Vitamin D, best known for its vital role in bone health, could also benefit mental health, weight loss, and stave off colds and flu
Credit: Getty
Often hailed as the 'sunshine vitamin',
Dr Asia Ahmed, GP and
"You could say it's a 'quiet hero'.
"It supports everything from bone strength and immunity to muscle function and mood, yet many people just don't get enough.
"Vitamin D is definitely one of the most important vitamins to take. Because we make vitamin D through sunlight exposure, and the sun isn't strong enough in the winter, deficiency is very common.
"That's why it's one of the few supplements the NHS recommends everyone consider during the colder months."
It costs as little as 2.2p per pill from high-street pharmacies.
From boosting mental health to aiding weight loss and the immune system, our experts share all the health
benefits
of vitamin D you need to know about.
Bone health
Vitamin D is vital when it comes to maintaining healthy teeth, muscles and bones.
It also helps our bodies absorb other nutrients - mainly increasing the amount of calcium and phosphate the gut can absorb from food into the bloodstream.
To supplement or not- The top 10 vitamins and minerals that are vital for health - and the best sources for each one
At the same time, it prevents calcium from being lost from the kidneys, which is why a vitamin D deficiency can impact bone health.
Not getting enough vitamin D can lead to serious bone-related conditions, says Dr Mohammad,
Najjar, Medical Director of
He warned: "Not getting enough vitamin D can negatively impact bone health causing
"In older people, a lack of vitamin D can contribute towards
Infection resistance
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Vitamin D supplementation has been shown to reduce the risk of acute respiratory infections
Credit: Getty
Vitamin D plays a crucial role in supporting immune function and potentially increases resistance to illness.
Not getting enough can leave your immune system vulnerable and more at risk of attack and infection.
In particular, it could reduce the risk of respiratory infections, said Dr Ajay Bagga, Senior General Practice Leader at Nuffield Health, helping to lower the likelihood of
A major study carried out by Queen Mary University of
London
found vitamin D supplementation reduced the risk of acute respiratory infections - with the effect being comparable to that of the flu vaccine.
And research by Bangor University found vitamin D supplementation, especially for those with low levels of the vitamin, can shorten the duration of a cold and lessen the severity of symptoms.
Hay fever
While evidence is still emerging, vitamin D may modulate immune response, potentially reducing inflammatory allergic reactions like hay fever.
Dr Najjar explained: "Because vitamin D plays an important role in maintaining a healthy immune system, people who are low in vitamin D could have a weakened immune system and may be more reactive to allergens and therefore experience stronger hay fever symptoms than if they had adequate levels of vitamin D."
Specifically, a recent
Mental health
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Supplementing with vitamin D may improve mood and mental clarity
Low vitamin D levels are linked to depression,
So supplementing with the vitamin may improve mood and mental clarity, especially in those who are deficient.
Dr Najjar explained: "Whilst vitamin D's role in bone health is widely known, more recent suggests it also plays an important role as a neuroprotective agent.
"This means that is can help to reduce neuroinflammation and support serotonin synthesis, improving brain plasticity.
"It's for this reason it's believed that healthy vitamin D levels can be important for mental health and deficiencies could be linked to depression as well as
Throughout autumn and winter, days are shorter and the cold weather prompts people to spend more time indoors. Therefore, a drop in vitamin D compared to summer is likely.
October through to March is when levels reach their lowest- and when it may be felt most in your mood.
So if you're a bit hit-and-miss with your supplements, this is the time to make sure you take them.
Dr Ahmed said: "Collective data from our customers over three years showed that vitamin D levels were lowest in January and highest in August and September.
"Levels fluctuate by over 15 per cent throughout the year — this is one of the many reasons why in winter, many people may develop symptoms, such as low mood."
Weight management
Vitamin D isn't a weight loss supplement, but it may support weight loss indirectly when paired with diet and exercise - especially if a person has vitamin D deficiency, which is more common in people with obesity.
Dr Najjar added: "It's believed vitamin D could help to reduce the formation of new fat cells in the body and also suppress storage of fat cells.
"It can also increase serotonin levels, which can help you to feel more full after eating."
Some
Biological ageing
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Vitamin D could stave off ageing with its ability to reduce inflammation and oxidative stress
Credit: Getty
Vitamin D plays a role in reducing inflammation and oxidative stress, which are key factors in ageing.
In this way, adequate levels may support healthy ageing, maintain muscle function, and protect against age-related diseases.
A new study also suggests vitamin D supplements may help preserve the lengths of the protective caps at the ends of telomeres, and it's believed that maintaining their length may help to slow down some aspects of biological ageing.
Dr Ahmed explained: "We have certain molecules (7-dehydrocholestrol, or 7DHC) in our skin.
"When sunshine hits our skin, the 7DHC molecules absrob the sunlight and become energised.
"They need to rearrange themselves to suit their new
energy
, and the first thing they rearrange into is pre-vitamin D3.
"The heat from our bodies transforms pre-vitamin D3 into vitamin D3, a form which can leave the skin and enter the bloodstream. There, it circulates to the liver and kidneys, where it is metabolised into usable forms."
Levels of 7DHC in our skin are thought to decrease by up to 50 per cent as we age.
One
Also, metabolic changes within the body reduce the capacity to process vitamin D and calcium, including changes in the liver and kidneys.
Fight cancer
Vitamin D may help regulate cell growth and prevent the formation of cancerous cells.
Dr Bagga said: "Some studies suggest that vitamin D deficiency increases the risk of certain
prostate, but findings are mixed.
"It's considered supportive but not curative."
Cancer Research UK does note there isn't enough convincing evidence to link low levels of vitamin D to cancer.
Should you take a vitamin D supplement?
Vitamin D is available from sunlight, food, such as fatty fish, egg yolks, and fortified milk and cereal.
Supplements are often needed if you have limited sun exposure, dark skin, or absorption issues.
Dr Bagga advised: "They're the most reliable way to ensure consistent intake."
In the UK, it's generally recommended to take a supplement containing 10 micrograms (10 μg, equivalent to 400 IU) of vitamin D daily in autumn and winter.
Dr Bagga adds before buying a vitamin D supplement, you should look for the following:
Vitamin D3 (cholecalciferol) – more effective than D2
Third-party testing (for purity and dose accuracy)
Oil-based softgels or drops – better absorption
TRY:
OR:
OR:
Dr Najjar added: "It's important to speak to your medical practitioner before embarking on any new course of supplements and always ensure that the supplements you're buying are from a trusted source, and in the correct dosage."
How much vitamin D do you need?
FROM about late March or early April to the end of September, most people should be able to make all the vitamin D they need from sunlight on their skin.
Children from the age of one year and adults need 10 micrograms (mcg) of vitamin D a day. This includes pregnant and breastfeeding women, and people at risk of vitamin D deficiency.
Babies up to the age of one year need 8.5 to 10 micrograms of vitamin D a day.
A microgram (mcg) is 1,000 times smaller than a milligram (mg). The word microgram is sometimes written with the Greek symbol μ followed by the letter g (μg).
Sometimes the amount of vitamin D is expressed as International Units (IU). One microgram of vitamin D is equal to 40 IU, so 10 micrograms of vitamin D is equal to 400 IU.
Source: NHS
How do you know if you're lacking vitamin D?
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Fatigue may be one of the first signs you're lacking vitamin D
Credit: Getty
Do you often feel tired, rundown, or struggle with muscle aches and pains? It could be a sign that you have vitamin D deficiency, especially if you spend little time outdoors, have darker skin, or are over 65 — all factors that can affect your ability to produce vitamin D.
Signs of vitamin D deficiency can be very different from one person to the
next
, but can include:
Fatigue
Bone or muscle pain
Frequent infections
Depression or mood changes
Slow wound healing
A blood test measuring vitamin D levels can also be confirm deficiency.
What happens if you take too much vitamin D?
In rare cases if you take too much vitamin D it can result in a buildup of calcium in the blood, a condition known as hypercalcemia.
Some of the first symptoms that your blood calcium level might be higher than normal include:
Feeling more tired than usual
Feeling weak
Not wanting to eat much
Constipation
Loss of concentration and interest in doing things
Mild confusion
Low mood
Irritability
If hypercalcemia is left untreated, it can lead to a range of serious health issues, from kidney problems and osteoporosis to neurological and cardiovascular complications, and in severe cases, it can even be fatal.
Dr Bagga urged: "You should always check with a healthcare provider before high-dose use."
