Micronutrients

micronutrients on a vegan diet

IODINE

WHAT IS IODINE AND WHERE DO WE FIND IT?

Iodine is a trace element which is found in the earth’s soil, however, the iodine content of the soil varies from region to region, hence the iodine content in foods is often unreliable.

WHY DO WE NEED IODINE?

  • Iodine is required for healthy thyroid function.
  • Every cell in our body depends on thyroid hormones for regulation of their metabolism, hence the importance for adequate iodine in our diets.
  • It’s worth noting that too much iodine can also cause abnormal thyroid function although most people are concerned with low iodine levels in their diet.

IODINE DEFICIENCY LEADS TO:

  • Symptoms of hypothyroidism: goitre, fatigue, weight gain, muscle cramps, cold intolerance, hair loss
  • can inhibit the brain development in foetus
  • impaired cognitive function

HOW MUCH IODINE DO WE NEED?

  • In the UK, the recommended daily intake for adults is 140mcg.
  • Intake shouldn’t exceed 600mcg per day.

WHERE CAN WE FIND IODINE?

  • In the UK and USA, iodine is found in cow’s milk since iodine solutions are used to clean cows’ teats and milking equipment which then end up in the milk.
  • Fortified salt (mandatory in Canada, but optional in the UK and USA); 1/4 tsp contains about 70mcg iodine.
  • Seaweed can contain varying levels of iodine, so caution is recommended to avoid toxicity. Furthermore, some seaweeds like hijiki can be contained with arsenic.
    1 1/2-2 nori sheets (4g) provides the recommended daily intake.
  • 1 cup boiled lima beans contains 16mcg idoine
  • 5 prunes have 13mcg iodine
  • Supplementation (including the Veg1 tablet from the Vegan Society)

CALCIUM

WHAT IS CALCIUM AND WHERE DO WE FIND IT?

Calcium is a mineral that is found in the soil and is then absorbed into the roots of plants.

WHY DO WE NEED CALCIUM?

  • To keep our teeth and bones healthy and strong (99% of calcium is in bones and teeth)
  • Muscle contraction
  • Nerve transmission
  • Normal heart rhythm
  • Wound healing
  • Calcium is stored in the skeleton and if the body needs calcium, it can draw on the reserves in the bones.

WHAT IS THE LINK BETWEEN VITAMIN D AND CALCIUM?

  • Our bodies need vitamin D in order to use calcium.
  • Vitamin D helps the calcium absorption from food. So, even if you consume enough calcium, it won’t be absorbed properly if you’re deficient in vitamin D.

CALCIUM DEFICIENCY LEADS TO

  • deficiency is not readily apparent
  • muscle spasm or cramps
  • brittle nails
  • fragile bones
  • tooth decay
  • numbness and tingling in hands

HOW MUCH CALCIUM DO WE NEED

  • In the UK, the recommended daily intake is 700mg per day.
  • Teenagers, breastfeeding women and those suffering from osteoporosis and inflammatory bowel disease require more (800-1250mg).
  • Intake should not exceed 2000mg since excess calcium can cause kidney stones.

WHERE CAN WE FIND CALCIUM

  • Green leafy vegetables that are low in oxalate (oxalate hinders calcium absorption): kale, broccoli, bok choy, turnip greens, collard greens
  • beans: 1 cup cooked chickpeas provides 80mg, 1 cup white beans 70mg
  • 1 cup dried figs has 300mg
  • Nuts, e.g. 20 almonds have 80mg, 2 tbsp tahini have 130mg, 1 tbsp chia seeds has 70mg
  • 1 cup cooked oats has 190mg
  • Although spinach and beet greens are high in calcium, they’re also high in oxalate, hence reduced calcium absorption!
  • AVOID calcium SUPPLEMENTS because they appear to increase the risk of heart disease, kidney disease as well as prostate cancer.

CALCIUM AND BONE HEALTH

To keep our bones healthy, our body needs more than calcium. Vitamin D, vitamin K and magnesium are also factors affecting bone health. Furthermore, performing weight-bearing exercises and maintaining a healthy body weight are also important.

SELENIUM

WHAT IS SELENIUM AND WHERE DO WE FIND IT?

Selenium is a trace element that is naturally found in the soil to varying degrees, hence the selenium level in plants depends on the amount of selenium in the soil the plants are grown.

WHY DO WE NEED SELENIUM?

  • Selenium is part of many enzymes which are substances that speed up the chemical reactions in our bodies.
  • It is an anti-oxidant and protects cell membranes and DNA from damage.
  • It helps the thyroid gland in the the production of thyroid hormones.
  • It plays an important role in fertility by protecting both the eggs and the sperm from free radical damage.

SELENIUM DEFICIENCY LEADS TO:

  • hypothyroidism (fatigue, mental slowing, hair loss, goitre)
  • nail discolouration
  • infertility
  • extreme deficiency can cause Keshan disease (cardiomyopathy) or Kashin-Beck disease (a type of osteoarthritis)

HOW MUCH SELENIUM DO WE NEED?

  • In the UK, the recommended daily intake is 60mcg for women and 75mcg for men.
  • Intake shouldn’t exceed 450mcg per day since too much selenium can cause selenosis (hair and nail loss or brittleness, skin rashes/lesions, nausea, vomiting)

WHERE CAN WE FIND SELENIUM?

  • One Brazil nut can contain 70-90 mcg selenium.
  • 100g of sunflower seeds contain about 55mcg selenium
  • 100g of sesame seeds contain 45mcg selenium.
  • Other foods with low amount of selenium: mushroom, tofu, carrots, raisins
  • In the UK, many cereals and wholegrain breads are fortified with selenium.
  • Animal products provide selenium because supplements are added to the feeds of the factory-farmed animals.

ZINC

WHAT IS ZINC AND WHERE DO WE FIND IT?

Zinc is an essential element that is found in mineral deposits in earth’s crust (usually with copper and lead) from which zinc is then extracted. The amount of zinc in plants depends on levels of the element in soil.

Small traces of zinc are also found in ocean water.

WHY DO WE NEED ZINC?

  • for growth and making new cells
  • wound healing
  • for a strong immune system and to fight infections
  • healthy vision
  • for carbohydrate metabolism
  • male reproductive health (promotes prostate health, normal sperm count

ZINC DEFICIENCY LEADS TO:

  • skin problems
  • hair loss
  • weak immune system (slow wound healing, recurrent colds)
  • fatigue
  • impaired vision

HOW MUCH ZINC DO WE NEED?

  • In the UK, the recommended intake is 7mg for women and 9.5mg for men
  • Taking high doses of zinc reduces the copper level your body absorbs. Do NOT exceed 25mg zinc per day.
  • Routine supplementation with zinc is NOT recommended!

WHERE CAN WE FIND ZINC?

  • 100g tempeh=3.3 mg zinc
  • 1/4 cup wheat germ=3.3mg zinc
  • 2 tbsp tahini=2.8mg
  • 2 tbsp pumpkin seeds=2.1mg
  • 1 cup cooked oatmeal=1.5mg
  • tofu, sunflower seeds, white beans, quinoa, lentils
  • Non-vegan sources: Oysters get zinc from sea water and are rich in zinc, however, the content of zinc in oysters depend of the zinc concentration of the water they grow.
  • Red meat and chicken contain zinc because either the supplements are added to their feeds or via the grass animals consume.

MAGNESIUM

WHAT IS MAGNESIUM AND WHERE DO WE FIND IT?

Magnesium is an essential element found in the earth’s crust. It occurs combined and can be extracted from minerals.

The amount of magnesium in plants depends on levels of the element in soil.

WHY DO WE NEED MAGNESIUM?

  • for nerve and muscle function
  • healthy immune system
  • strong bones
  • for energy metabolism
  • for blood pressure regulation

MAGNESIUM DEFICIENCY LEADS TO:

  • muscle twitching and cramps
  • abnormal heart rhythm
  • sleep disorders
  • depression
  • fatigue

HOW MUCH MAGNESIUM DO WE NEED?

  • In the UK, the recommended intake is 300mg for men, and 270mg for women.
  • Do NOT exceed 400mg as it causes diarrhoea.
  • Routine supplementation is NOT recommended!

WHERE CAN WE FIND MAGNESIUM?

  • 100g wholewheat bread=82mg magnesium
  • 28g almonds=80mg magnesium
  • 1/2 cup boiled spinach=78mg magnesium
  • 1/2 cup cooked black beans=60mg magnesium
  • 1 cup avocado=44mg magnesium
  • peanuts, potato, brown rice, kidney beans, dark chocolate

COPPER

WHAT IS COPPER AND WHERE DO WE FIND IT?

Copper is an essential mineral that is found in mineral deposits in earth’s crust. It can then be extracted.

The amount of copper in plants depends on the soil type and levels of the element in soil.

WHY DO WE NEED COPPER?

  • essential for manufacture of collagen which is one of the main proteins in bones, cartilage, tendons and skin
  • is an antioxidant
  • for formation of red blood cells
  • for energy metabolism
  • important for iron absorption

COPPER DEFICIENCY LEADS TO:

  • Copper deficiency is extremely RARE!
  • signs of anaemia (tiredness, pallor)
  • weak and brittle bones
  • memory problems

HOW MUCH COPPER DO WE NEED?

  • In the UK, the recommended intake is 1.2mg per day.
  • Do NOT exceed 10mg as it causes copper toxicity (diarrhoea, stomach pain, damage to liver and kidney).
  • Supplementation is NOT recommended!

WHERE CAN WE FIND COPPER?

  • 1/4 cup cashews=0.88mg copper
  • 1/2 cup shiitake mushrooms=0.65mg copper
  • 1/4 cup sunflower seeds=0.63mg copper
  • sesame seeds, soybeans, spinach, beans, olives, sweet potato

IRON

WHAT IS IRON AND WHERE DO WE FIND IT?

Iron is an essential mineral that’s typically abundant in the soil in form of ferric oxide. Plants can absorb iron from this chemical. Animals get iron by eating grass, however, factory-farmed animals have iron supplements added to their feeds.

WHY DO WE NEED IRON?

  • for oxygen transport (is part of haemoglobin in red blood cells and myoglobin in muscle)
  • is a component of some proteins and enzymes
  • helps maintain a normal immune system

IRON DEFICIENCY LEADS TO:

  • tiredness
  • feeling cold
  • shortness of breath
  • pallor
  • inability to concentrate

HOW MUCH IRON DO WE NEED?

  • In the UK, the recommended daily intake is 8.7mg, however, menstruating women need 14.8mg a day.
  • High doses of iron on a vegan diet are very unlikely unless you take supplements. Doses of 20mg per day can cause constipation, vomiting and abdominal pain.

WHERE CAN WE FIND IRON?

  • 1 cup cooked lentils=6.6mg iron
  • 28g (1oz) pumpkins seeds=4.2mg iron
  • 1 cup cooked quinoa=2.8mg iron
  • 1 cup cooked broccoli=1mg iron
  • 2 slices wholemeal bread=1.5mg iron
  • dried apricots, figs, tofu, tempeh, cabbage, kale, dark chocolate
  • Vitamin C increases the absorption of iron whereas tea and coffee reduce the absorption.
  • Although spinach is high in calcium, they’re also high in oxalate, hence reduced iron absorption!

VITAMIN B12

VITAMIN B12 (COBALAMIN)

  • Vitamin B12 comes from the bacteria that live in the soil, but because of our hygienic lifestyles those microorganisms are destroyed, hence the need for supplementation.
  • Animal products provide vitamin B12 because supplements are added to the feeds of the factory-farmed animals.

WHY DO WE NEED VITAMIN B12?

  • crucial for our metabolism
  • protects nerve cells and helps with their normal growth
  • helps make red blood cells

VITAMIN B12 DEFICIENCY

  • Vitamin B12 is preserved very well in the body and the body’s stores can last for about 3 years before any deficiency becomes apparent.
  • Vitamin B12 absorption decreases with age; 10-15% of people over 65 have vitamin B12 deficiency.
  • Vegans, vegetarians and elderly people are at risk of vitamin B12 deficiency as are some meat-eaters.
  • Risk of vitamin B12 deficiency is increased if you suffer from atrophic gastritis or conditions affecting your small intestine (Crohn’s, coeliac disease), or if you’re taking certain medication such as proton pump inhibitor (medication for heartburn) or metformin (for diabetes).

SIGNS AND SYMPTOMS OF DEFICIENCY

  • numbness and tingling
  • memory loss
  • anaemia with fatigue, pallor and shortness of breath

HOW MUCH DO WE NEED?

  • In the UK, the recommended intake is 1.5mcg for adults, in the USA, it’s 2.4 micrograms a day. However, when taking supplements higher doses are recommended because of the poor absorption of supplements.
  • Aim for doses of 25-100μg daily or a 2000μg weekly dose. Individuals over 50 years or with conditions like coeliac disease might need at least 50μg
  • Supplements – There are 2 different types: cyanocobalamin and methylcobalamin. Most supplements contain cyanocobalamin and this is suitable for the majority of people.
  • Vitamin B12 can also be found in fortified foods such as cereals, nutritional yeast, some plant-based milks and plant-based cheeses. Make sure you consume enough in order to get your recommended daily intake.
  • Lastly, get your blood levels checked to ensure they are adequate.

VITAMIN E

VITAMIN E (ALPHA-TOCOPHEROL)

Vitamin E is fat-soluble vitamin and is found naturally in many foods.

WHY DO WE NEED VITAMIN E?

  • acts as an anti-oxidant (helps protect cells from damage caused by free radicals).
  • boosts immune system
  • protects red blood cells and important for their maintenance
  • helps the blood vessels widen and prevents blood clotting
  • may prevent Alzheimer’s disease

VITAMIN E DEFICIENCY

  • very rare!
  • almost always as a consequence of poor fat digestion and absorption eg: in Crohn’s disease, cystic fibrosis

SIGNS AND SYMPTOMS OF DEFICIENCY

  • nerve and muscle damage
  • loss of feeling in legs and arms
  • poor control of body movement
  • vision problems
  • weak immune system

HOW MUCH DO WE NEED?

  • In the UK, the recommended daily intake is 4mg for men and 3mg for women, however, the RDA in the USA is 15mg/day.
  • Vitamin E supplements are NOT recommended. There’s some evidence that supplementation might be harmful.
  • Vitamin E is made up of 8 compounds, however, as long as one compound is available in a supplement, it can be sold as vitamin E which causes an imbalance and inhibits the absorption of the other compounds.

FOODS HIGH IN VITAMIN E

  • nuts, seeds and nut butters are the best sources of vitamin E.
  • green leafy vegetables (spinach and broccoli), avocados, asparagus

VITAMIN C

VITAMIN C (ASCORBIC ACID)

  • Vitamin C is a water soluble vitamin which the body doesn’t store, so we need to consume food rich in vitamin C on a daily basis.
  • Vitamin C can’t be found in useful amounts in cooked animal products.

WHY DO WE NEED VITAMIN C?

  • helps make collagen, a protein and a component of connective tissue (bone, ligament, skin, blood vessels…)
  • essential for growth and repair of all tissues
  • necessary for wound healing
  • is an antioxidant (may reduce risk of some cancers and stroke)
  • helps the absorption of iron

VITAMIN C DEFICIENCY LEADS TO

  • bleeding gums
  • loose teeth
  • swollen joints
  • anaemia causing tiredness
  • slow wound healing
  • Severe vitamin C deficiency leads to scurvy.

HOW MUCH DO WE NEED?

  • In the UK, the recommended daily intake is 40mg for adults. Higher doses are recommended for pregnant women.
  • Smokers have lower vitamin C levels and require 35mg more per day.

FOODS HIGH IN VITAMIN C

  • Orange, kiwi, grapefruit, red and green pepper, broccoli, cabbage, cauliflower, potato
  • Vitamin C is sensitive to heat and light. Try to eat fruits and vegetables raw or lightly cooked.
  • Canned fruits and vegetables are low in vitamin C because the canning process exposes them to high heat.
  • Since it’s water-soluble, it can get lost during cooking. Avoid boiling; steaming is better.
  • Routine supplementation is NOT recommended.
  • Note: vitamin C supplements do NOT prevent common cold nor do they reduce the symptoms of a cold.
  • Note: you can only get the anti-oxidant benefits of vitamin C from foods and NOT from vitamin C supplements!

VITAMIN A

VITAMIN A (RETINOID AND CAROTENOID)

  • Vitamin A is a fat soluble vitamin.
  • Preformed vitamin A (retinoid) is found in animal products.
  • Plant foods contain provitamin A (carotenoid) which the body can convert to vitamin A as needed, hence no risk of overdose or toxicity.

WHY DO WE NEED VITAMIN A?

  • vital for growth and development
  • essential for vision
  • healthy skin and tissues
  • acts as anti-oxidant
  • normal functioning of immune system
  • may reduce risk of some cancers including lung and prostate cancer.

VITAMIN A DEFICIENCY LEADS TO

  • skin infections
  • mouth ulcers
  • thrush
  • dry hair, dry eyes
  • in extreme cases: night blindness

HOW MUCH DO WE NEED?

  • In the UK, the recommended daily intake is 0.7mg for men, and 0.6mg for women.
  • Routine supplementation is NOT recommended.
  • Preformed vitamin A in animal products can be toxic. High doses over 1.5mg/day may affect your bones, making you prone to fractures.
  • Pregnant women should avoid high doses of vitamin A from animal sources since it can harm the unborn baby.
  • It’s impossible to have too much vitamin A from plant sources since our body stops converting the beta-carotene to vitamin A.

FOODS HIGH IN VITAMIN A

  • Best sources: sweet potato and carrot
  • Butternut squash, spinach, collard, apricots
  • Note: including small amounts of fat can increase the absorption of carotenoids.

VITAMIN B9

VITAMIN B9 (FOLATE/FOLIC ACID)

  • Vitamin B9 is a water-soluble vitamin and since it can’t be stored in the body, it needs to be taken in the diet every day.
  • Folate is derived from the Latin word ‘folium’ meaning leaf which points to where we can find folate: in leafy green vegetables.
  • Folate is found naturally in foods whereas folic acid refers to the fortified foods and supplements.

WHY DO WE NEED VITAMIN B9?

  • Brain and nerve function
  • Production of new cells
  • Works with vitamin B12 to produce red blood cells

FOLATE DEFICIENCY LEADS TO

  • tongue ulcers
  • cognitive problems
  • digestive problems
  • symptoms of anaemia: fatigue, difficulty concentrating, headache, heart palpitations, shortness of breath
  • changes in skin pigmentation

HOW MUCH DO WE NEED?

  • In the UK, the recommended daily intake is 200 mcg for adults.
  • Women who want to become pregnant, need to take 400 mcg of folic acid 3 months before and 12 weeks after pregnancy to prevent neural tube defects in baby.
  • Avoid doses of 1000 mcg of folic acid per day since high levels can mask vitamin B12 deficiency.

FOODS HIGH IN FOLATE

  • Legumes, asparagus, leafy green vegetables, Brussels sprouts, beets, nuts and seeds
  • Fortified nutritional yeast

VITAMIN B1

VITAMIN B1 (THIAMINE)

  • Vitamin B1 is a water-soluble vitamin and since it can’t be stored in the body, it needs to be taken in the diet every day.
  • Thiamine is made only in bacteria, fungi, and plants. Animals and humans need to get it from their diet.

WHY DO WE NEED VITAMIN B1?

  • important for energy metabolism (converting carbohydrates into energy), hence important for growth, development and function of cells
  • important for nerve function
  • muscle contraction

THIAMINE DEFICIENCY LEADS TO

  • weight loss and anorexia
  • confusion, short term memory loss
  • muscle weakness
  • cardiovascular symptoms
  • Wernicke-Korsakoff syndrome: thiamine deficiency common in people with chronic alcoholism
  • Beriberi: rare, peripheral neuropathy and wasting, congestive heart failure
  • groups at risk of deficiency: alcohol dependency, elderly, HIV/AIDS patients, diabetics, post bariatric surgery, people on kidney dialysis

HOW MUCH DO WE NEED?

  • In the UK, the recommended daily intake is 1mg for men, and 0.8mg for women.
  • No evidence to suggest adverse effects from high thiamine intakes, however, it’s recommended not to exceed 100mg per day.

FOODS HIGH IN THIAMINE

  • Whole grains (wholemeal/wholewheat bread/spaghetti), black beans, acorn squash, sunflower and sesame seeds, nuts
  • Fortified nutritional yeast
  • Fortified breakfast cereals
  • Note: Heating foods containing thiamin can reduce their thiamine content.
  • Since thiamine dissolves in water, a large amount is lost when cooking water is thrown out.
  • Also, processing foods reduces the thiamine content, for example white rice or white flour are poor sources unless fortified.

VITAMIN B7

VITAMIN B7 (BIOTIN)

  • Vitamin B7 is a water-soluble vitamin and was formerly called vitamin H or co-enzyme R. Since it is water-soluble, it can’t be stored in the body.
  • Biotin is found naturally in some foods, but some is also made by bacteria in the gut.

WHY DO WE NEED VITAMIN B7?

  • essential for metabolising carbohydrates, fat and amino acids
  • important in gene regulation and cell signalling
  • essential for healthy hair, nails and skin
  • important for the developing foetus in pregnant women

BIOTIN DEFICIENCY

  • is rare!
  • signs and symptoms: thinning hair with progression to loss of all hair on the body; scaly, red rash; skin infection; brittle nails; depression, lethargy

HOW MUCH DO WE NEED?

  • In the UK, there’s no clear recommendation. Most sites recommend a daily intake of 50mcg per day.
  • In the US, an intake of 30mcg per day is recommended for adults; this recommendation is also supported by WHO.
  • Biotin is believed not to be susceptible to loss during cooking.
  • Routine supplementation is not recommended since most people consume adequate amounts.

FOODS HIGH IN BIOTIN

  • Nuts and seeds
  • Fortified nutritional yeast
  • Tempeh, oats, avocado, spinach, broccoli, tempeh