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Description Beta-carotene is a precursor form of vitamin A.  It is converted to vitamin A in the body on an ‘as-required’ basis.
Function/ Used for In its unconverted form, beta-carotene acts as an antioxidant in the body, neutralising potentially damaging free radicals.

If it is converted in the body then its actions are those of vitamin A.

Intake Recommended intake

EU NRV: Not established.

 

UK average daily intake

In the UK, the average adult diet provides 2.58 mg (beta-carotene) daily.1

Five portions of fruit and vegetables per day will usually provide about 6mg of beta-carotene. However, apples, bananas and onions provide almost no beta-carotene.

As a supplement Not generally available as a single supplement. Commonly available as part of a multivitamin and mineral formula.

Different multivitamin and minerals products will vary in the percentage NRVs they include. People should always check the label for information about a specific product.

Found in (dietary sources) Beta-carotene gives yellow and orange fruit and vegetables their colour. Therefore, rich sources include brightly coloured fruit and vegetables such as carrots, red pepper, spinach (and other dark green leafy vegetables), mango, peaches and apricots (60 per cent of the average UK intake comes from carrots).

Levels are stable during cooking, but losses occur due to exposure to light and air.

Deficiency There are no known deficiency symptoms.
Precautions and contraindications High intakes are not recommended for smokers. Two large-scale studies have shown an association between beta-carotene supplementation (20mg/day) and an increased incidence of lung cancer in smokers and individuals with previous high-level exposure to asbestos.2,3

Safe Upper Level: 7mg/day4

Use in pregnancy and breastfeeding Beta-carotene is converted to vitamin A in the body on an ‘as required’ basis which reduces the risk of vitamin A toxicity. This makes it safe during pregnancy when high levels of vitamin A itself (retinol) should be avoided.
Interactions e.g. with other medications Beta carotene may interact with alcohol increasing the liver toxicity of alcohol5
Adverse effects Carotenoids are generally non-toxic.

Intake of >30mg daily may lead to hypercarotenemia which is characterised by a yellowish colouration of the skin (including soles of feet and palms of hand). This is harmless and reversible.6

References 1 DEFRA. Family Food 2014.UK Purchases and expenditure on food and drink and derived energy and nutrient intakes. National Statistics, December 2015. https://www.gov.uk/government/statistics/family-food-2014

2 The Alpha-Tocopherol, Beta Carotene Cancer Prevention Study Group. (1994) The effect of vitamin E and beta carotene on the incidence of lung cancer and other cancers in male smokers. New England Journal of Medicine 330, 1029-1035.

3 Omenn, G.S., Goodman, G.E., Thornquist, M.D., Balmes, J., Cullen, M.R., Glass, A., Keogh, J.P., Meyskens, F.L., Valanis, B., Williams, J.H., Barnhart, S., Hammer, S. (1996). Effects of a combination of beta-carotene and vitamin A on lung cancer and cardiovascular disease. New England Journal Medicine 334, 1150-1155

4 Expert Group on Vitamins and Minerals, 2003.

5 Leo M. A & Lieber C.S. Alcohol, Vitamin A and βcarotene: adverse interactions including hepatotoxicity and carcinogenicity. American Journal of Clinical Nutrition. June 1999 vol 69:6 pp1071-1085 http://ajcn.nutrition.org.content/69/6/1071.full

6 Mason, P. Dietary Supplements. Pharmaceutical press, London, 2001

 

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Description Closely related to the blueberry, bilberry is a shrubby perennial bush that grows in the forests and on the moors of northern Europe.

The main active ingredients are anthocyanins, chemical compounds with antioxidant and anti-inflammatory properties.

Function/ Used for Bilberry is widely used for supporting eye health. The antioxidant anthocyanidin compounds protect blood vessels, including the capillaries which help deliver oxygen rich blood to the eyes.
Intake N/A
As a supplement Bilberry is generally available as fresh or dried berries; and as bilberry extract usually standardised to 25% anthocyanidin.

Dose: 160-480mg daily.1

Tablets providing 50-120mg of anthocyanins per day have been typically used in clinical trials2.

Found in (dietary sources) N/A
Deficiency N/A
Precautions and contraindications Very high doses should be avoided in patients with haemorrhagic (bleeding) disorders.
Use in pregnancy and breastfeeding There is no evidence of adverse effects in pregnancy when consumed in dietary amounts, however safety is not known when used in larger quantities.
Interactions e.g. with other medications Warfarin and other anti-coagulant and anti-platelet (blood thinning) medication.3
Adverse effects None known
References 1 Williamson, E. M. Potter’s Herbal Cyclopaedia. C.W. Daniel Co Ltd. 2003

2 Mills, S. & Bone, K. Principles and practice of phytotherapy. Churchill Livingstone, 2000.

3 Braun & Cohen. Herbs and Natural Supplements: An evidence-based guide. Churchill Livingstone, 2005.

 

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Description Formerly known as Vitamin H or Co-enzyme R, biotin is a water soluble vitamin and a member of the B-vitamins group.
Function/ Used for Biotin works synergistically with other B vitamins. It is involved in energy production through the metabolism of carbohydrates, proteins and fats. It is also essential for the production of RNA and DNA and helps to maintain the mucous membranes, healthy skin and nails.
Intake Recommended intake

EU NRV: 50µg

 

UK average daily intake

Requirements vary depending on age and gender. The UK National Diet and Nutrition Survey lists up-to-date intake requirements and average intakes1.

As a supplement Not generally available as a single supplement. Commonly available as part of a multivitamin and mineral formula.

Different multivitamin and minerals products will vary in the percentage NRVs they include. People should always check the label for information about a specific product.

Found in (dietary sources) Biotin is found in many foods and is also synthesised by the microflora in the gut.

The richest sources of biotin are liver, kidney, egg yolks, brewer’s yeast and soya beans. Meat, wholegrain cereals, wholemeal bread, milk and cheese are also good sources. Green vegetables contain very little biotin.

Deficiency Symptoms include patches of hair loss (alopecia), reversible baldness, depression, muscle pains and wasting. Also, dry, flaky skin, rash around the eyes, nose and mouth, brittle hair, tiredness and loss of appetite.
Precautions and contraindications Safe Upper Level: 970µg/day2
Use in pregnancy and breastfeeding Suitable to be used during pregnancy and breastfeeding.
Interactions e.g. with other medications Biotin may interact with anticonvulsant drugs. Long term treatment with anticonvulsant drugs may decrease blood levels of biotin. To avoid side effects, individuals taking anticonvulsants should supplement with biotin either alone or as part of a multivitamin. 3,4
Adverse effects None known.
References https://www.gov.uk/government/collections/national-diet-and-nutrition-survey

2 Expert Group of Vitamins and Minerals, 2003.

3 Mason, P. Dietary Supplements. Pharmaceutical Press, London, 2001.

4. Gaby, A. R. A-Z Guide to Drug-Herb-Vitamin Interactions. HealthNotes 2006.

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