Vitamins and minerals Flashcards
What are the fat soluble vitamins?
Vitamins A, D, E and K
What is vitamin A important for?
Vision in dim light, maintains mucous membranes, maintains skin, and is essential for growth.
What is vitamin K essential for?
Formation of blood-clotting proteins, in particular prothrombin.
Where is vitamin K mainly synthesised?
In the gut by the resident bacteria.
What foods are the main sources of vitamin K?
Dark green leafy veg, such as broccoli, sprouts, kale and spinach.
What are the names of the 2 main sources of vitamin K i.e. K1 and K2?
Phylloquinone (K1) and menaquinone (K2).
What is the dietary reference value (DRV) for vitamin K?
Between 0.5 and 1.0 microgram/kg body weight/day.
Is taking mg levels (excess) of natural vitamin K toxic?
No.
What effect does excessive intake of synthetic vitamin K have?
Haemolysis and liver damage.
Who may need vitamin K supplements?
Newborn babies and anybody who has undergone a long course of antibiotics which has killed off their gut flora, preventing them from producing vitamin K.
What is “haemorrhagic disease of the new-born”?
The inability to produce blood clots due to newborns having no existing gut flora to produce vitamin K. This is treated by an injection of vitamin K at birth.
Do fat-soluble vitamins need to be consumed every day?
No, the body can store these.
What foods are good sources of vitamin A?
Liver, carrots, dairy products and spinach.
What are good dietary sources of vitamin D?
Oily fish and eggs.
What are the best dietary sources of vitamin E?
Vegetable oils, avocados, nuts and seeds.
Can water-soluble vitamins be stored in the body?
No, except for vitamin B12 which can be stored in the liver.
Which vitamins are water-soluble?
Vitamin C and the vitamin B-complex group of vitamins.
Which water-soluble vitamins frequently work together and share similar functions?
B vitamins.
What is the primary role of B vitamins?
They facilitate various steps of energy production within the body.
Which vitamins are easily washed out or destroyed during food storage and preparation?
Water-soluble vitamins (B vitamins and vitamin C).
Which is the only water-soluble vitamin that can be stored in the body?
Vitamin B12, which is stored in the liver.
What food sources provide vitamin B12?
Animal foods, such as, shellfish, meat, liver, kidney, fish, eggs, milk and milk products.
Which vitamins act as co-enzymes?
The water-soluble ones i.e. vitamin C and B vitamins.
Which vitamins are heat labile (unstable and likely to change or decompose under heat)?
The water-soluble vitamins i.e. vitamin C and B vitamins.
What functions does Vitamin C have in the body?
It is involved in the formation of collagen, aids wound healing and iron absorption, and has strong antioxidant properties.
What accelerates the destruction of vitamin C?
Light, heat, alkali, air, physical processing and cooking.
What are the best techniques for cooking foods to avoid destroying vitamin qualities?
Stir-frying, steaming, and microwaving.
What can prolonged deficiency of vitamin C lead to?
Poor wound healing, bone weakening, and scurvy.
What are the symptoms of scurvy?
Swollen, bleeding gums, bleeding spots around hair follicles; possibly followed by subcutaneous bleeding.
What is the RNI (reference nutrient intake) for vitamin C?
40 mg per day.
Very high doses (1g or 1000mg) of vitamin C can lead to what symptoms?
Diarrhoea and kidney stones.
What are the 2 forms of vitamin C shown on food labels?
Ascorbic acid and dehydroascorbic acid.
Does smoking increase the need for vitamin C?
Yes, smoking increases the rate at which the body uses vitamin C and in turn increases the body’s intake requirement.
Which vitamin aids iron absorption and is essential for the structure of connective tissue and bone?
Vitamin C.
What is the other name for vitamin B1?
Thiamine
What is the other name for Thiamine?
Vitamin B1
What is the function of vitamin B1 (thiamine)?
Involved in the release of energy from carbohydrates, important for the brain and nerves that utilise glucose for their energy needs, and helps support proper heart function.
Is thiamine (vitamin B1) stable or unstable?
Unstable - easily destroyed by cooking and storage with up to 20% of its value being lost in food preparation.
What are the initial symptoms of vitamin B1 deficiency?
Poor appetite, fatigue and weight loss.
After 10 days, symptoms of vitamin B1 deficiency can appear, and what can they progress to?
Muscle weakness, nerve damage affecting hands and feet, heavy legs, and headaches.
What is beriberi?
An advanced form of vitamin B1 deficiency which can cause problems with the nervous system, heart and lungs.
Why do alcoholics sometimes develop a vitamin B1 (thiamine) deficiency, a vitamin B3 (niacin), or a vitamin B6 deficiency?
Excessive alcohol intake significantly reduces the body’s ability to absorb these vitamins from food.
What 2 foods are particularly good sources of thiamine (vitamin B1)?
Pork and yeast.
Name 6 other good sources (excluding pork and yeast) of thiamine (vitamin B1).
Green vegetables, root vegetables, seeds, mushrooms, tuna and fortified cereals.
What is the reference nutrient intake (RNI) of thiamine (vitamin B1)?
0.4mg/1000kcal
What 5 symptoms have very high intakes (e.g. 3g/day) of thiamine (vitamin B1) been linked with?
Headaches, irritability, insomnia, a rapid pulse, and weakness.
What is the other name for vitamin B2?
Riboflavin
What vitamin is also known as Riboflavin?
Vitamin B2
What is the functions of riboflavin (vitamin B2)?
It is involved with all the energy pathways in the body, in particular energy release, especially from fat and protein.
What can a deficiency in riboflavin (vitamin B2) cause?
Changes to the mucous membrane and skin around the mouth and nose.
Various skin complaints are often associated with which type of vitamins deficiency?
B vitamins.
What are 8 rich sources of vitamin B2 (riboflavin)?
Liver, cheese, eggs, yeast extract, milk, yoghurt, green vegetables, fortified cereals.
How much riboflavin (vitamin B2) content does milk lose per hour when exposed to the sun?
10%
What is the dietary reference value (DRV) for riboflavin (vitamin B2)?
1.1 mg/day for females and 1.3 mg/day for males.
Is excessive intake of riboflavin (vitamin B2), toxic?
No, toxicity is rare even on high intakes, and the body will excrete the excess.
What is the other common name for vitamin B3?
Niacin
What is the vitamin name for Niacin?
Vitamin B3
What vitamin are nicotinic acid and nicotinamide alternative names for?
Vitamin B3 (niacin).
What are the functions of vitamin B3 (niacin, nicotinic acid, nicotinamide)?
Involved with energy production, particularly the breakdown of glucose, amino acids, fatty acids and the metabolism of folate and vitamin C. It is also required for the development, maintenance and function of skin, the digestive system and nervous system and is vital in the manufacture of DNA.
What condition can a deficiency in niacin (vitamin B3) lead to?
Pellagra
What are the symptoms of pellagra (a condition caused by deficiency in niacin/vitamin B3)?
Fatigue, loss of appetite, muscle weakness, anxiety. The lining of the mouth and tongue become inflamed and more advanced symptoms include diarrhea, skin rashes and delirium. Pellagra can be fatal.
Is vitamin B3 (niacin) deficiency often seen in developed countries?
No, it is extremely rare.
What 7 foods are rich sources of vitamin B3 (niacin)?
Liver, beef, pork, mutton and other meats, fish, yeast extract, and fortified cereals.
What are the recommended intakes of niacin (vitamin B3) for optimal health?
6.6 mg/1000 kcal or 12-18 mg per day.
Are very high intakes (3-6 g per day) of niacin (vitamin B3) dangerous?
Yes, they can cause liver damage.
What is vitamin B6 a mixture of?
Pyridoxine, pyridoxal, and pyridoxamine.
Which vitamin is particularly associated with amino acid metabolism?
Vitamin B6.
What are the 5 functions of vitamin B6?
Associated with amino acid metabolism, plays a role in fat metabolism, involved in the metabolism of glycogen in the muscle, protects the body against infection, and plays a vital role in producing haemoglobin.
Is a severe clinical deficiency of vitamin B6 rare?
Yes
What are the 5 symptoms of a (rare) deficiency in vitamin B6?
Anaemia, a smooth tongue, cracks at the corner of the mouth, dermatitis and muscular system problems.
What 5 things can cause a vitamin B6 deficiency?
Ageing, alcoholism, a high protein diet, abnormal eating patterns, and some medical conditions.
Why can ageing cause a vitamin B6 deficiency?
There is a decline in B6 due to changes in absorption and metabolism of the vitamin. n
Why does a high protein diet cause a quick depletion of vitamin B6?
Requirements for B6 are related to the amount of amino acids to be metabolised.
What are 5 examples of diseases which can decrease levels of vitamin B6 in the blood?
Asthma, kidney disease, Hodgkin’s disease, sickle-cell anaemia, and diabetes.
Name 7 rich food sources of vitamin B6
Liver, meat, whole cereals, walnuts, bananas, salmon, and peanuts.
What is the RNI for vitamin B6?
1.2-1.4 mg/day.
What has excessive intakes (doses from 50-500mg/day) of vitamin B6 been associated with?
Disturbances in the sensory nervous pathways.
Why is vitamin B6 one of the most popular supplements in the UK?
Probably due to the belief that it is effective in treating pre-menstrual syndrome.
Why can it not be concluded that high dose supplements (50-100mg) of vitamin B6 are effective in treating PMS?
Although it appears to be effective, none of the reviewed studies were randomised controlled trials (the gold standard of clinical testing).
What are the 5 main functions of vitamin B12?
Required for normal growth and development, plays a vital role with folate for the production of normal red blood cells, is important in the protection and function of nerve cells, the manufacture of DNA and metabolism of fats and carbohydrates.
What vitamin is especially important for babies, young children and teenagers?
Vitamin B12 - it is required for normal growth and development.
How many years can it take to develop a deficiency in vitamin B12?
30 years - although it is water-soluble, it can be stored in the liver.
Describe the unique process by which vitamin B12 is absorbed.
It has to be taken up in the blood and needs to bind to a protein called “intrinsic factor” which is produced in the stomach.
What condition may be caused by a deficiency of vitamin B12 in the diet?
Megaloblastic anaemia - red blood cells are abnormally large and inefficient at carrying oxygen. A deficiency of folate can also lead to this condition.
What condition may be caused by a lack of vitamin B12 due to an inability to produce “intrinsic factor”?
Pernicious anaemia - the symptoms are similar to megaloblastic anaemia.
What vitamin may vegan or vegetarians not have sufficient stores of?
Vitamin B12.
What 4 food groups contain vitamin B12?
Meat, fish, eggs and dairy products.
What 8 specific foods are the major sources of vitamin B12?
Meats, offal, cod, salmon, haddock, halibut, clams and shrimps.
What 3 non-meat/non-fish products are useful sources of vitamin B12?
Milk, fortified breakfast cereals, and yeast extract (such as Marmite).
What vitamin do plant foods not contain any of?
Vitamin B12.
What is the RNI for vitamin B12?
1.5 microgram/day.
Does vitamin B12 have excellent antioxidant properties?
No.
Biotin is a member of which group of vitamins?
B-complex vitamins.
What 4 functions does biotin have?
A co-enzyme for carboxylase which carries CO2 units in metabolic pathways, a central role in lipogenesis (the synthesis of fatty acids in the cell), a central role in gluconeogenesis (formation of glucose from other sources such as amino acids), and is involved in catabolism (breakdown) of branched chain amino acids.
Is biotin deficiency common or rare?
Rare, because all foods contain significant quantities of biotin, and many are rich in biotin.
What are the symptoms of the rare nutritional disorder of biotin deficiency?
Loss of hair or fine scaly dermatitis.
Can the gut flora produce biotin?
Yes.
Name 10 good food sources of biotin.
Egg yolk, liver, legumes, oats and grains, almonds and walnuts, chickpeas (canned), yellow split peas, green split peas, brown lentils and lima (butter) beans (canned).