Vitamin C Explained: Food Sources, Forms and UK Intake

Vitamin C is one of the best known vitamins, and one of the easiest to get from food. Your body cannot make or store it, so you need some every day. This guide covers what vitamin C does, where to find it, the forms you will see on supplement labels and how much is enough.

What vitamin C does

Vitamin C has a long list of authorised health claims in Great Britain. Word for word:

• Vitamin C contributes to the normal function of the immune system.
• Vitamin C contributes to normal collagen formation for the normal function of skin.
• Vitamin C increases iron absorption.
• Vitamin C contributes to the protection of cells from oxidative stress.
• Vitamin C contributes to the reduction of tiredness and fatigue.
• Vitamin C contributes to normal energy-yielding metabolism.
• Vitamin C contributes to normal psychological function.

How much vitamin C do you need?

The NHS says adults aged 19 to 64 need 40 mg of vitamin C a day, and that you should be able to get all you need from a varied and balanced diet. On labels, the Nutrient Reference Value (NRV) is 80 mg, so a product with 80 mg provides 100% NRV.

The NHS also says that taking less than 1,000 mg of vitamin C supplements a day is unlikely to cause any harm, and that large amounts, more than 1,000 mg a day, can cause stomach pain, diarrhoea and flatulence. These symptoms should go away once you stop taking so much.

The best food sources of vitamin C

• Citrus fruit, such as oranges, and orange juice
• Red and green peppers
• Strawberries and blackcurrants
• Kiwi fruit
• Broccoli and Brussels sprouts
• Potatoes

Vitamin C is sensitive to heat and dissolves in water, so long boiling reduces it. Eating some fruit and vegetables raw, or steaming them briefly, keeps more of the vitamin.

Vitamin C and iron

One of the most practical facts about vitamin C is the authorised claim that vitamin C increases iron absorption. Pairing iron-containing plant foods, such as beans, lentils, fortified cereals or leafy greens, with a source of vitamin C, such as peppers, tomatoes or a glass of orange juice, is a simple habit, particularly for people on a plant-based diet.

Forms of vitamin C on supplement labels

Ascorbic acid

The standard form, chemically the same as the vitamin C found in fruit and vegetables. It is the form most supplements use.

Vitamin C with citrus bioflavonoids

Ascorbic acid combined with bioflavonoids, compounds found naturally in the peel and pith of citrus fruit. Bioflavonoids themselves carry no authorised health claims, so the claims above relate to the vitamin C content.

Liposomal vitamin C

Vitamin C enclosed in phospholipids, such as sunflower lecithin. It is a different format that some people prefer. As with any form, compare the amount of vitamin C per capsule and the %NRV.

Buffered forms

Sodium ascorbate and calcium ascorbate are mineral salts of vitamin C. If you use them, remember they also add sodium or calcium to your daily total.

Our vitamin C products

• Vitamin C + Citrus Bioflavonoids 500mg Vegan Capsules: 425 mg vitamin C as ascorbic acid (531% NRV), 70 mg citrus bioflavonoids extract and 5 mg magnesium per capsule. 1 to 2 capsules daily.
• Liposomal Vitamin C 1000mg per Serving Vegan Capsules: 500 mg vitamin C as liposomal L-ascorbic acid (625% NRV) with 100 mg sunflower lecithin per capsule. 1 to 2 capsules daily. Two capsules provide 1,000 mg, so start with one, and speak to your doctor or pharmacist if you plan to take two a day long term.

Both are high-strength compared with the NRV and are made with vegan HPMC capsules. Find more in our Immune Support collection and in Beauty and Skin.

Who should speak to a doctor or pharmacist first

• Anyone pregnant, trying for a baby or breastfeeding
• Anyone taking prescription medication or under medical supervision
• Anyone with a history of kidney stones, a kidney condition or a condition affecting iron levels
• Anyone under 18, as our products are not intended for under 18s

Frequently asked questions

How much vitamin C should I take a day?

The NHS says adults need 40 mg a day, which most people get from food. If you take a supplement, the NHS says less than 1,000 mg a day is unlikely to cause harm. Follow the label and do not exceed the recommended daily dose.

Can you take too much vitamin C?

Yes. More than 1,000 mg a day can cause stomach pain, diarrhoea and flatulence, according to the NHS.

Is liposomal vitamin C better than ascorbic acid?

It is a different format rather than a different vitamin. We do not claim one is better than the other. Choose on the amount of vitamin C you want per serving, the number of capsules and your own preference.

Does vitamin C stop colds?

Food supplements are not intended to prevent, treat or cure any illness. The authorised claim is that vitamin C contributes to the normal function of the immune system.

When is the best time to take vitamin C?

Whenever suits your routine. If you have a sensitive stomach, taking it with food is often more comfortable.

This article is for general information and is not medical advice. Food supplements should not replace a varied, balanced diet and a healthy lifestyle. Do not exceed the recommended daily dose.

Sources

• NHS. Vitamin C.
• Department of Health and Social Care. Great Britain nutrition and health claims register.