Tom Sanders, Professor of Nutrition and Dietetics at King’s College London, says there is no ‘magic pill’ when it comes to nutrition, and as taking supplements often goes hand in hand with a healthy diet, it can be difficult to evaluate their benefits.
Last year alone, we spent a total of £398million on them. But will taking supplements really make us healthier?
Furthermore, nutrients from food are sometimes more readily absorbed and used by the body than those in a pill.
Here, with the help of Professor Sanders and Ursula Arens of the British Dietetic Association, we sift the science from the sales pitch to bring you the ultimate guide to the nutrients that are vital for good health...
VITAMIN A
VITAL FOR: Sight and bones, and to make infection-fighting white blood cells. Despite lab studies suggesting anti-cancer properties, there’s no evidence that A protects against tumours.
RECOMMENDED DAILY AMOUNT (RDA): 0.7mg for men; 0.6 for women.
GOOD FOOD SOURCES: Pumpkin, carrots, sweet potato.
LIKELIHOOD OF DEFICIENCY: Rare.
RISKS FROM TAKING SUPPLEMENTS: In smokers, 20mg a day has been linked to a greater risk of lung tumours. Long-term intake of 1.5mg a day increases the risk of osteoporosis. Vitamin A causes birth defects, so avoid during pregnancy.
VITAMIN B
VITAL FOR: Healthy metabolism, immunity and nervous system. Recent study found B6 and B12 stalled brain shrinkage linked to dementia; B6 and B12 also shown to reduce homocysteine, a chemical linked to cardiac risk. But studies suggest greatest benefits in reducing the risk of heart disease occurred only in those whose levels were low.
RDA: B6, 1.4 mg a day for men, 1.2 mg for women; B9, 2mg for adults; B12, 0.0015mg for adults.
GOOD FOOD SOURCES: Wholegrain foods and fortified cereals. Meat, eggs and dairy products are only reliable dietary sources of B12.
LIKELIHOOD OF DEFICIENCY: Vegans at risk of low B12. Over 60s often low in B6 and B12. Alcohol inhibits absorption of B6.
RISKS FROM TAKING SUPPLEMENTS: Taking more than 200mg of B6 can cause nerve damage.
Red Peppers are a good source of Vitamin C
VITAMIN C
VITAL FOR: Bones, teeth, gums and blood vessels. No evidence supplementation prevents colds except in those exposed to severe cold or bursts of heavy physical activity.
RDA: 40mg.
GOOD FOOD SOURCES: Red peppers, citrus fruit, broccoli.
LIKELIHOOD OF DEFICIENCY: Pregnant women, smokers and heavy drinkers.
RISKS FROM TAKING SUPPLEMENTS: The Food Standards Agency advises against taking more than 1,000mg a day. Too much can cause headaches and diarrhoea.
VITAMIN D
VITAL FOR: Healthy bones and teeth. Evidence it protects against heart disease, some cancers, diabetes and asthma, and even helps weight control.
RDA: None set because most of our intake comes from sunlight.
GOOD FOOD SOURCES: Fatty red meat (sausages), oily fish, eggs, margarine.
DEFICIENCY: Widespread in winter because of a lack of sunshine.
RISKS FROM TAKING SUPPLEMENTS: A daily intake of 25-50mcg may increase risk of kidney stones.
VITAMIN E
VITAL FOR: Promoting healthy red blood cells and preventing clots. It’s not one vitamin, but a group of eight compounds. Dietary intake refers to alpha-tocopherol - the most readily absorbed form. People with the highest blood levels have the lowest risk of heart disease, but there is no evidence supplements help those with existing cardiac problems
RDA: 4mg for men; 3mg for women.
GOOD FOOD SOURCES: Wheatgerm, almonds, sunflower seeds, hazelnuts.
DEFICIENCY: Rare.
RISKS FROM TAKING SUPPLEMENTS: May suppress good HDL cholesterol if taking statins.
FOLIC ACID
VITAL FOR: Prevention of spinal birth defects. Linked to lower risk of dementia and bowel cancer. Some evidence for reduction of cardiac and stroke risk.
RDA: 2mg; 4mg during pregnancy and for women planning to conceive.
GOOD FOOD SOURCES: Spinach, peas, fortified cereals, asparagus.
DEFICIENCY: Most likely among the elderly and heavy drinkers.
RISKS FROM TAKING SUPPLEMENTS: Supplementation could mask B12 deficiency, which is more common in the elderly. This is because it corrects the anaemia caused by low B12, but not nerve damage.
GLA (Omega-6)
VITAL FOR: Skin, hair and the immune system. The European Food Safety Authority says there is no evidence for claims that GLA (gamma linolenic acid) aids bone health, blood pressure, cholesterol or weight control.
RDA: None set. It is one of the few nutrients that we get in excess because of our high intake of vegetable oils.
GOOD FOOD SOURCES: Vegetable oils.
DEFICIENCY: None. Excess common.
RISKS FROM TAKING SUPPLEMENTS: Because they use similar chemical pathways, omega-6 suppresses absorption of heart-protective omega-3. A ratio of four parts omega-6 to one of omega-3 is ideal, but in the UK it is around 15 to one. This imbalance is linked to inflammation and increased risk of breast cancer, asthma and obesity. To restore the balance, increase omega-3 intake from oily fish, and avoid supplements such as evening primrose oil which are high in 6.
HESPERIDIN
VITAL FOR: Healing, immune system and healthy blood vessels. Studies show benefits for varicose veins and haemorrhoids. In supplements, is usually combined with vitamin C.
RDA: None set.
GOOD FOOD SOURCES: Citrus fruit, blackberries, apricots.
DEFICIENCY: Not known.
RISKS FROM TAKING SUPPLEMENTS: Supplements interact with blood thinners such as warfarin.
Egg yolk is a good source of iron
IRON
VITAL FOR: :Energy.
RDA: 8.7mg for men, 14.8mg for women.
GOOD FOOD SOURCES: Red meat, beans, dried fruit, egg yolk, oysters and mussels.
DEFICIENCY: One in ten women is estimated to have low levels: vegetarians and vegans are also at risk. One in four babies over six months has low levels, with those given cow’s milk before 12 months most at risk. Tea and coffee inhibit uptake.
RISKS FROM TAKING SUPPLEMENTS: Avoid taking more than 17mg daily as this could cause nausea, diarrhoea and block uptake of calcium and zinc.
(ROYAL) JELLY
VITAL FOR: Royal jelly is rich in pantothenic acid, which appears to lower cholesterol. Trials in the 1980s found 300mg lowered cholesterol in patients with abnormally high cholesterol levels. Cancer-fighting claims not proven.
RDA: None set.
GOOD FOOD SOURCES: Produced by bees — sold as a dietary supplement.
DEFICIENCY: Deficiency of pantothenic acid is rare.
RISKS FROM TAKING SUPPLEMENTS: Royal jelly can trigger asthma and anaphylaxis, with any form of allergy increasing the danger. Interacts with warfarin, increasing risk of bleeding.
VITAMIN K
VITAL FOR: Blood clotting and bones. Studies suggest it protects against liver and prostate cancers. May reverse hardening of arteries.
RDA: 0.001mg per kg of body weight, so a person weighing 60kg needs 0.060mg.
GOOD FOOD SOURCES: Dark green vegetables such as kale and spinach.
DEFICIENCY: More likely if taking large doses of vitamins A and/or E, as both inhibit uptake.
RISKS FROM TAKING SUPPLEMENTS: None known. Taking up to 1mg a day unlikely to cause harm.
LYCOPENE
VITAL FOR: Lycopene is a plant chemical that gives red pigment to tomatoes. Activates lung enzymes that protect against tumours.
RISKS FROM TAKING SUPPLEMENTS: None known.
GOOD FOOD SOURCES: Cooked tomatoes and ketchup.
DEFICIENCY: No evidence.
RDA: None set. U.S. Food and Drug Administration found benefits for eating at a cup of cooked tomatoes or sauce a week, but not supplements. Lycopene may be more readily absorbed when combined with a fat, such as olive oil.
MAGNESIUM
VITAL FOR: 300 biochemical reactions, including metabolising energy from food. Low levels are a factor in migraine, obesity and PMS.
RDA: Minimum of 300mg for men, 270mg for women.
GOOD FOOD SOURCES: Oatbran, bulgar, pearl barley.
DEFICIENCY: Most likely in the elderly, those with IBS, Crohn’s disease and gastric disorders. Also occurs with poorly controlled diabetes, diuretics prescribed for high blood pressure, some chemotherapy drugs and antibiotics.
RISKS FROM TAKING SUPPLEMENTS: People with kidney disease should avoid supplements because they cannot excrete excess.
NIACIN (B3)
VITAL FOR: Nervous and digestive systems. It’s known to convert dangerous LDL cholesterol into cardiac-protective HDL. Studies show 1,000 to 2,000mg three times a day lowers unhealthy LDL cholesterol.
RDA: 17mg a day for men, 13mg for women.
GOOD FOOD SOURCES: Beef, pork, chicken, fortified cereals.
DEFICIENCY: Rare.
RISKS FROM TAKING SUPPLEMENTS: Up to 500mg daily is safe. More than 1,000mg can cause flushing, birth defects and eye problems.
Oily fish are a good source of Omega-3
OMEGA-3
GOOD FOR: Protecting against cardiovascular disease. The European Food Safety Authority has ruled there is no convincing evidence of brain boosting benefits in children.
RDA: None set, but the FSA advises girls, women who may conceive or those who are pregnant or breastfeeding to eat two 140g portions of oily fish weekly; boys and men should eat four.
GOOD FOOD SOURCES: Oily fish.
DEFICIENCY: Very common.
RISKS FROM TAKING SUPPLEMENTS: Depending on the supplement source, toxins in fish.
POTASSIUM
VITAL FOR: Fluid balance and reducing high blood pressure. Studies confirm low levels linked to stroke. Good evidence it improves bone density.
RDA: 3,500mg.
GOOD FOOD SOURCES: Tomato products, orange juice, dates.
DEFICIENCY: Commonly associated with high salt intake. Diarrhoea and prolonged sweating also deplete levels.
RISKS FROM TAKING SUPPLEMENTS: Avoid supplements in old age, as declining kidney function reduces ability to excrete excess. High doses can cause nausea, abdominal pain and vomiting.
QUERCETIN
GOOD FOR: May relieve allergy symptoms such as sneezing and itching. Lab studies have shown it stalls cancer cells and prevents damage caused by ‘bad’ LDL cholesterol; reduces blood pressure.
RDA: None set. Daily dose of 730mg showed blood pressure benefits.
GOOD FOOD SOURCES: Black and green tea, red onion, red berries.
DEFICIENCY: No evidence for deficiency.
RISKS FROM TAKING SUPPLEMENTS: Animal studies have shown increased risk of kidney tumours with long-term high doses.
Red wine is a good source of resveratrol
RESVERATROL
GOOD FOR: This compound is thought to explain the heart-protective benefits of red wine. Lab tests show it reduces activity of enzymes which drive cancer and stalls signals tumours use to grow and spread. Resveratrol also prevents inflammation and vascular damage.
RDA: None set.
GOOD FOOD SOURCES: Red wine from pinot noir grapes.
DEFICIENCY: No evidence for deficiency.
RISKS FROM TAKING SUPPLEMENTS: Supplements vary in concentration and may contain emodin, a laxative.
SELENIUM
VITAL FOR: Preventing cell damage and helping immunity and thyroid function. Large studies have proved link between lack of selenium and increased cancer risk, but trials of supplements have been inconclusive in all but prostate cancer. Selenium appears to help asthma and male infertility.
RDA: 75mcg for men, 60 for women.
GOOD FOOD SOURCES: Two brazil nuts provide the RDA; crab, salmon and halibut.
DEFICIENCY: Common. Average UK intake is half the recommendation.
RISKS FROM TAKING SUPPLEMENTS: The FSA says up to 35mg daily is safe; higher levels may be toxic.
THIAMIN
VITAL FOR: Metabolising your food - low levels lead to tiredness and irritability; cardiac function and nervous system.
RDA: 1mg for men, 0.8 for women.
GOOD FOOD SOURCES: Fortified cereals, pork, milk.
DEFICIENCY: Most likely in smokers or if taking antacids, diuretics or undergoing chemotherapy. A diet high in sugar and simple carbohydrates also a risk. Alcohol, tea, coffee and sulfite preservatives (in wine) inhibit uptake.
RISKS FROM TAKING SUPPLEMENTS: Up to 100mg considered safe. However, supplements can disrupt the heart medicine digoxin and diuretics. Antibiotics can increase uptake by killing friendly gut bacteria that feed on thiamin.
URSOLIC ACID
GOOD FOR: Some evidence this plant chemical (found in a range of fruit and herbs) could enhance effect of chemotherapy and radiotherapy.
RDA: None set.
GOOD FOOD SOURCES: Apples; cranberries, peppermint, oregano.
DEFICIENCY: None.
RISKS FROM TAKING SUPPLEMENTS: None known.
VANADIUM
GOOD FOR: Thyroid function. Some evidence low levels linked to cardiac risk.
RDA: None set. FSA advises intake from food sufficient.
GOOD FOOD SOURCES: Shellfish, wholegrains, mushrooms.
DEFICIENCY: None.
RISKS FROM TAKING SUPPLEMENTS: Can cause nausea, cramp and diarrhoea, supplements with vanadium are banned by the EU but are still sold on the internet.
WHEY
GOOD FOR: Reducing blood pressure and improving vascular function. Preserves lean muscle during weight loss. May help regulate blood glucose levels by improving release of insulin to mop up blood sugar.
RDA: None set
GOOD FOOD SOURCES: Dairy produce.
RISKS FROM TAKING SUPPLEMENTS: Possible problems if intolerant to dairy.
XANTHOPHYLLS
GOOD FOR: This family of yellow plant pigments includes the antioxidants lutein zeaxanthin and cryptoxanthin - these are also found in the eye and high levels are associated with reduced risk of age-related macular degeneration. Studies suggest cryptoxanthin may protect against lung cancer.
RDA: None set.
GOOD FOOD SOURCES: Spinach, kale, pumpkin, tangerines.
DEFICIENCY: Absorption may decline with age.
RISKS FROM TAKING SUPPLEMENTS: None identified.
YEAST
GOOD FOR: Brewer’s yeast is a rich source of B-vitamins and the minerals chromium and selenium. Chromium improves glucose control in diabetics. Patchy evidence for cholesterol control.
RDA: None set.
GOOD FOOD SOURCES: Comes only as a supplement.
DEFICIENCY: High-sugar diet depletes chromium.
RISKS FROM TAKING SUPPLEMENTS: True yeast intolerance is rare, but can occur in those with compromised immune system, such as chemotherapy patients.
ZINC
VITAL FOR: Healthy immune system. Low levels during pregnancy increase risk of having a premature or low birthweight baby.
RDA: 5.5 to 9.5mg for men; 4 to 7 mg for women.
GOOD FOOD SOURCES: Oysters, fortified cereals, baked beans, beef.
DEFICIENCY: Most likely in the elderly, diabetics and vegetarians.
RISKS FROM TAKING SUPPLEMENTS: FSA advises no more than 25mg daily. Higher doses can block other vital nutrients including iron.
Read more: http://www.dailymail.co.uk/health/article-1315772/Which-supplements-YOU-take.html?ITO=1490#ixzz10sxmB8c4
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