nutrition

• why are vitamins and minerals necessary?

  they are necessary in small amounts for life and growth - for normal metabolism and good health. Important for every cell in the body
• vitamins and minerals act as 'chemical partners' with key roles in lots of vital processes including:

  • metabolism
  • cell production
  • tissue repair
• minerals and vitamins are chemical partners or co-factors for various enzymes or structural substances in tissues such as bone and blood
• what can deficiencies in minerals and vitamins have an effect on?

  Deficiencies have an adverse effect on metabolism, cell production, and tissue repair and specific diseases can be linked to lack of individual vitamins.
• how are vitamins obtained?

  Obtain from food or supplements - body does not make sufficient quantities
• which vitamins can be made by the body from non-dietary sources?


  Only two vitamins (vitamin d and vitamin k) can be made by the body from non-dietary sources
• vitamins are organic molecules
• how many water-soluble vitamins are there?

  9
• name all the water-soluble vitamins

  • Vitamin B1 (thiamine)
  • Vitamin B2 (riboflavin)
  • Vitamin B3 (niacin)
  • Vitamin B5 (pantothenic acid)
  • Vitamin B6 (pyridoxine)
  • Vitamin B7 (biotin)
  • Vitamin B9 (folate/folic acid)
  • Vitamin B12 (cobalamin)
• where are the water-soluble vitamins absorbed?

  Most water-soluble vitamins absorbed in the upper small intestine (duodenum) except for vitamin B12

  • Vitamin B12 absorbed in the ileum – binds to intrinsic factor (protein secreted by the stomach)
• how are water-soluble vitamins stored?

  They are not stored in the body. Water soluble – not stored in the body and so excreted from the body in urine
• name the fat-soluble vitamins

  • Vitamin A
  • Vitamin D
  • Vitamin E (tocopheryl)
  • Vitamin K
• what does vitamin D include?

  • Vitamin D - includes ergocalciferol (calciferol, vitamin D2), colecalciferol (vitamin D3), dihydrotachysterol, alfacalcidol (1α-hydroxycholecalciferol), and calcitriol (1,25-dihydroxycholecalciferol)
• where are fat-soluble vitamins absorbed?

  • absorbed by bile in the large intestine
  • Absorption can be reduced if fat absorption is decreased e.g. by lack of pancreatic enzymes/low-fat diet
• where are fat-soluble vitamins stored?

  In the body
• vitamin deficiencies

  A) B9

  B) immune

  C) clotting

  D) nerve

  
• what are minerals?

  Inorganic substances with a specific chemical composition and crystal structure.
• minerals are required in large amounts but particularly which ones?

  sodium and potassium
• what are trace elements?

  Trace elements are chemical elements that are required in very small amounts for the proper functioning of organisms.
• what are the variety of functions of minerals?

  • Formation of bones and teeth
  • Essential constituents of body fluids, tissues and blood
  • Components of enzyme systems
  • Nerve function
• name the minerals

  • Sodium
  • Magnesium
  • Potassium
  • Chloride
  • Phosphorus
  • Iron
  • Zinc
• name some trace elements

  • Selenium
  • Copper - can test for copper for liver conditions
  • Iodine
• trace elements won't be seen in blood tests usually
• what are the sources of minerals for our body?

  • Food and supplements
  • No one food provides all
  • Need a healthy balanced diet
  • Water is also a source
• absorption of minerals may be affected by:

  • Presence of other minerals/vitamins
  • Components found in food
  • Amount of mineral already in body
• what is the potential effect of a potassium and magnesium deficiency?

  cardiac arrhythmias (heart rhythm changes) - or even excess potassium 
• examples of mineral deficiencies and potential effects:

  • Calcium and Magnesium - osteoporosis
  • Calcium and Magnesium - muscle cramps and tetany
  • Zinc - hair loss and poor wound healing
  • Iron - anaemia
  • Copper - Wilson’s disease (can cause liver problems)
• what are the recommendations for vitamins and minerals for those who are pregnant?

  • Recommended women of childbearing age take 400μg folic acid supplement daily until the 12th week of pregnancy
  • NHS Health Start Scheme (pregnant and breastfeeding women) – free vitamin supplement containing 10μg of vitamin D, 400 micrograms of folic acid and 70 mg of vitamin C
• when is a higher dose of folic acid recommended in pregnant women?

  • If family history of neural tube defects - a higher dose of 5mg of folic acid daily recommended
  • Women with diabetes and those taking anti-epileptic medicines may also need to take a higher dose of folic acid
• what is the recommendation of vitamin D in children?

  • Breastfed babies (birth to one year of age) - a daily supplement containing 8.5 - 10μg of vitamin D
  • Babies fed infant formula – not required unless < 500ml of infant formula a day as formula milk fortified
  • Children aged 1 to 4 years old - daily supplement containing 10μg of vitamin D
  • Consider a vitamin D supplement containing 400–600 international units (IU) daily ages 4-18
• what is the recommendation of vitamins A and C for children?

  • Children aged six months to five years – daily supplement of vitamins A and C (often combined with vitamin D)
  • Precautionary measure - ensure requirements are met (difficult to be certain diet provides a reliable source)
  • Babies fed infant formula – not required until receiving less than 500ml of infant formula a day - because infant formula is fortified with certain nutrients, including vitamins A and C
• recommendations of vitamin D for adults...

  • Adults with risk factors should take a daily supplement containing 400 international units (IU) of vitamin D throughout the year
  • Other adults should consider taking a daily supplement containing 400 IU of vitamin D, particularly in the autumn and winter
• lack of vitamin D is associated with what?

  associated with osteoporosis, cancer, cvd, MS, diabetes, poor immune function
• People at a higher risk of a vitamin D deficiency include those:

  • With limited sun exposure
  • With dark skin (for example African, African-Caribbean, or Asian or Middle-Eastern ethnic origin)
• Vitamin D deficiency can also occur in people who:

  • Are at increased risk of nutritional deficiency, for example vegans and those who do not eat fish
  • Are pregnant or breastfeeding
  • Are elderly (65 years and older)
  • Have certain conditions (such as a malabsorption syndrome) or are taking certain drugs (anti-epileptic drugs)
  • Are obese or have had gastric bypass surgery
  • Have a family history of vitamin D deficiency
• what causes of a vitamin D deficiency requires vitamin D in pharmacological doses?

  intestinal malabsorption or chronic liver disease
• what should be prescribed if patients with severe renal impairment require vitamin D therapy?

  the hydroxylated derivatives alfacalcidol or calcitriol as Vitamin D requires hydroxylation by the kidney to its active form.
• what groups of people may benefit from supplementation?

  • Some vegans - depends on their diet
  • People in certain demographic groups - infants and children, adolescents (iron deficiency), pregnancy and breastfeeding, elderly, ethnic minorities
  • Chronic alcoholism - poor diet and poor GI absorption - mainly vitamin B1
  • Innate GI malabsorption e.g. coeliac, inflammatory bowel disease (IBD) -lack of intrinsic factor, therefore, B12 deficiency
  • Chronic kidney disease (CKD) – vitamin D
  • If prescribed certain medications e.g. isoniazid therapy (deficiency in B6 may occur)
• what does fortification mean?

  Addition of nutrients to appropriate food vehicle
• examples of fortification...

  • Vitamin D fortified margarine
  • B vitamins and iron in cereals
  • White and brown flour fortified with calcium, iron, thiamine and niacin
  • Fluoride in drinking water