Most people in the UK already get enough vitamin C from food. A single orange covers your entire daily requirement, and if you eat a reasonable mix of fruit and vegetables, you’re almost certainly fine.
That might sound odd coming from someone who runs a supplement company. But it’s the reason we don’t sell vitamin C, and it’s worth understanding why.
What Vitamin C Does (and Doesn’t Do)
Vitamin C is a water-soluble vitamin that your body needs for immune function, collagen production, wound healing, and antioxidant protection. It’s involved in iron absorption and helps maintain healthy skin, cartilage, and bones.
What it doesn’t do is prevent colds. The idea that megadosing vitamin C wards off illness is one of the most persistent health myths around. A Cochrane review (Hemilä and Chalker, 2013, updated 2023) covering 29 trials and over 11,000 participants found that regular vitamin C supplementation did not reduce the incidence of colds in the general population. It may shorten the duration slightly, by about 8% in adults, but that’s roughly half a day off a week-long cold.
For most people, that’s not a compelling reason to take a daily supplement.
How Much Do You Need?
The NHS recommends 40mg of vitamin C per day for adults. That’s a low bar to clear from diet alone.
To put it in context: a medium orange contains about 70mg. A red bell pepper has over 120mg. Even a serving of broccoli or a handful of strawberries gets you there. If you eat any combination of fruit and vegetables daily, you’re very likely already meeting or exceeding the recommendation.
Your body can’t store vitamin C because it’s water-soluble. Any excess is excreted through urine. Taking high-dose supplements (above 1,000mg per day) can cause digestive issues including nausea, stomach cramps, and diarrhoea. There’s no benefit to megadosing, and there’s a small but real downside.
When a Vitamin C Supplement Might Make Sense
There are situations where supplementation is reasonable. If you eat very little fruit and vegetables, smoke (which depletes vitamin C faster), or have a medical condition affecting nutrient absorption, a low-dose supplement can fill the gap.
But for the average UK adult eating a halfway decent diet, vitamin C is one of the last things you need to worry about supplementing.
Where Your Supplement Budget Matters More
I started Epsilon Life because I wanted to focus on the gaps that diet genuinely struggles to fill. Vitamin C isn’t one of them. These are.
Vitamin D3 with K2
Unlike vitamin C, vitamin D is nearly impossible to get enough of in the UK for much of the year. Between October and March, UK sunlight doesn’t contain enough UVB radiation to trigger vitamin D synthesis in the skin. The NHS and Public Health England recommend that everyone in the UK consider supplementing vitamin D during autumn and winter, and many people would benefit from year-round supplementation. Our guide to vitamin D deficiency symptoms covers the UK-specific picture in detail.
Vitamin K2 works alongside D3 to direct calcium into bones and teeth rather than soft tissue. The two are more effective together than either alone. Our D3K2 supplement also includes zinc and boron for bone and immune support.
Magnesium
Magnesium is involved in over 300 enzymatic reactions in the body, including muscle function, sleep regulation, and energy production. Despite this, studies consistently show that a large proportion of the UK population doesn’t get enough from diet. Modern farming practices have reduced magnesium levels in soil, and processed foods are particularly low in it.
Unlike vitamin C, you can’t easily fix a magnesium shortfall by eating one piece of fruit. The richest food sources (pumpkin seeds, dark chocolate, spinach) need to be eaten consistently and in meaningful quantities. For many people, supplementation is the practical solution. We use magnesium glycinate specifically because it’s well absorbed and gentler on the stomach than cheaper forms like oxide or citrate. If you want to understand the differences between forms, our guide to magnesium glycinate benefits covers dosage, uses, and what the research shows.
Gut health
Your gut microbiome affects digestion, immune function, mood, and nutrient absorption. It’s also something that deteriorates with age, antibiotic use, stress, and a diet high in processed food. While eating fermented foods like yoghurt, kefir, and sauerkraut helps, most people don’t consume them regularly enough to maintain a diverse microbiome.
Our Biome Bliss is a fermented liquid gut health drink designed to support microbial diversity. It’s a different approach from capsule-based probiotics, and it fits into a daily routine more easily than trying to eat kimchi every morning.
The Point Isn’t to Sell You More Supplements
If anything, the point is the opposite. Vitamin C is a good example of a nutrient where the supplement industry has created demand that doesn’t match the science. Most people don’t need it in pill form.
The supplements worth taking are the ones where the gap between what your body needs and what your diet realistically provides is hardest to close. In the UK, that’s vitamin D (especially in winter), magnesium (widespread dietary shortfall), and increasingly gut health support as we learn more about the microbiome’s role in overall wellbeing.
Focus on the basics. Get your vitamin C from food. And if you’re going to spend money on supplements, spend it where it makes a measurable difference.
FAQ
How much vitamin C do I need per day?
The NHS recommends 40mg per day for adults. A single medium orange provides about 70mg, so most people who eat some fruit or vegetables daily already meet this requirement without supplementation.
Does vitamin C prevent colds?
No. A large Cochrane review found that regular vitamin C supplementation does not reduce the frequency of colds in the general population. It may shorten the duration by about 8%, roughly half a day, but does not prevent them.
Can you take too much vitamin C?
Yes. Because vitamin C is water-soluble, excess is excreted in urine, but doses above 1,000mg per day can cause nausea, stomach cramps, and diarrhoea. The NHS upper tolerable limit is 1,000mg per day. There is no benefit to megadosing.
What are the best food sources of vitamin C?
Red bell peppers (over 120mg per serving), oranges (about 70mg), kiwi fruit, strawberries, broccoli, and Brussels sprouts are all rich sources. A varied diet with regular fruit and vegetables will comfortably cover your daily needs.
Is vitamin C or vitamin D more important to supplement?
For most UK adults, vitamin D is far more important to supplement. UK sunlight is too weak between October and March to produce vitamin D in the skin, and dietary sources are limited. Vitamin C, by contrast, is abundant in common foods and easy to get enough of through diet alone.
What are the signs of low vitamin C?
Early signs include fatigue, irritability, and slow wound healing. More severe deficiency can cause bleeding gums, joint pain, dry skin, and easy bruising. True deficiency (scurvy) is rare in the UK but can occur in people with very restricted diets, heavy alcohol use, or certain medical conditions.
Do I need to take vitamin C with iron supplements?
Vitamin C helps your body absorb non-haem iron (the type found in plant foods and supplements). If you’ve been advised to take iron tablets, taking them with a glass of orange juice or alongside a vitamin C-rich food can improve absorption. You don’t necessarily need a separate vitamin C supplement for this.
What supplements should I actually take?
This depends on your diet and lifestyle, but the nutrients hardest to get from food alone in the UK are vitamin D (especially in winter), magnesium (widespread dietary shortfall), and omega-3 fatty acids (if you don’t eat oily fish regularly). Gut health support is also increasingly recognised as valuable. Always consult your GP or a registered dietitian for personalised advice.
References
- Hemilä H, Chalker E. (2013, updated 2023). Vitamin C for preventing and treating the common cold. Cochrane Database of Systematic Reviews. Full text
- NHS. Vitamin C. NHS website
- Public Health England. (2016). SACN vitamin D and health report. Full text
This article is for general information only and is not medical advice. If you’re unsure about your nutritional needs, consult your GP or a registered dietitian.
