W5.1_Vitamins, Minerals, and Nutrition

Question 1

What are the properties and purpose of vitamins? Name examples of water-soluble and fat-soluble vitamins. What are their properties? How can some of the vitamins be made in the body?

Answer 1

• Essential for life, necessary in small amounts, does not provide energy, obtained from diet
• Organic molecules, only vitamin D and K can be made by body
• Key in processes: metabolism, cell production, tissue repair
• Water-soluble vitamins: vitamin B and C
• Rapidly absorbed in duodenum (except B12 in ileum that binds to intrinsic factor)
• Not stored in body, excreted in urine
• Fat-soluble vitamins: vitamin A, D, E, K
• Absorbed by bile in small intestine (dependent on fat absorption, affected by pancreatic enzymes/diet)
• Stored in body, cannot be excreted
• Vitamin K: produced by GI flora (affected by antibiotics, can affect warfarin/anticoagulants)
• Vitamin D: can be synthesised in skin via cholesterol by sunlight

Question 2

State the symptoms of different vitamin deficiencies.

Answer 2

A: Poor night vision/night blindness
B1: Fatigue, loss of appetite, weight loss, GI effects
B2: Soreness of mouth and tongue, itching eyes, loss of vision
B3: GI effects, skin changes, tremors
B5: Fatigue, heart and digestive issues
B6: Depression, vomiting, increased susceptibility to disease, anaemia
B7: Skin inflammation, conjunctivitis
B9: Anaemia, digestive disorders, palpitations, behavioural disorders
B12: Pernicious anaemia, neurological issues
C: Scurvy, aching joints, generalised weakness
D: Bone changes/osteoporosis, poor immune function
E: Anaemia, nerve damage
K: Abnormal clotting

Question 3

What are the properties and purpose of minerals? Name some of the essential minerals.

Answer 3

• Inorganic substances, trace elements required in smaller amounts, have variety of function
• Obtained in food/supplements, water
• Absorption affected by presence of other minerals/vitamins, components in food, minerals already in body
• Calcium, sodium, magnesium, potassium, chloride, phosphorous, iron, iodine, selenium, zinc, copper

Question 4

State the symptoms of different mineral deficiencies.

Answer 4

• Potassium/magnesium: cardiac arrhythmias
• Calcium/magnesium: osteoporosis, muscle cramps, tetany
• Zinc: hair loss, poor wound healing
• Iron: anaemia
• Copper: Wilson’s disease

Question 5

Apart from the recommendations written in reference nutrient intakes (RNIs), what are the additional recommendations for people who are pregnant and children. Are there any more additional groups that require more vitamin or mineral supplements?

Answer 5

• Pregnancy: 400µg folic acid supplement daily until 12th week to prevent birth defects of central nervous system (higher dose of 5mg for family history of neural tube defects or with diabetes/taking anti-epileptic medicines), prevent excess vitamin A that causes teratogenic
• Children: extra supplements of vitamin A/C/D at different stages, especially breast-fed babies
• Other groups: vegans, some demographics, chronic alcoholism, innate GI malabsorption, chronic kidney disease, prescribed certain medications (ex. isoniazid)

Question 6

Briefly state some examples of fortification. What are the cons of buying supplements? Briefly explain some interactions between medication and vitamins or minerals (4). What is the role of pharmacist for that?

Answer 6

• Fortification: vitamin D in margarine, B vitamins/iron in cereals, calcium/iron/thiamine/niacin in white and brown flour, fluoride in drinking water
• Supplements: often anecdotal, might cause toxicity and accumulation
• Interactions: methotrexate and folic acid treatment, vitamin C improves iron absorption, tetracyclines and metal ions reduces antibiotic absorption, corticosteroids reduce calcium absorption
• Role of pharmacist: advice, identify patients that may benefit from supplements, aware of deficiency symptoms, recommend appropriate supplements, prevent interactions, not for profit

Question 7

Explain the consequences of malnutrition. What is the targeted patient group and purpose of nutritional support?

Answer 7

• Malnutrition: cause and consequence of ill health, increase vulnerability to disease
• Weakness and loss of muscle mass, apathy and depression, reduced immune response, poor wound healing, increased morbidity and mortality
• Nutritional support: for patients that don’t meet their requirements by eating/drinking normally
• Aim to provide normal feeding aim (≠ normal amount)

Question 8

Name the different types of oral nutritional support. In what occassion would it be prescribed?

Answer 8

• Oral nutritional support: sip feeds, milk-based (ready to drink/powdered), fruit juice based, semi-solid feeds, high protein supplements, energy supplements
• Prescribed in certain circumstances, usually short-term (∵ unpalatable)

Question 9

What is the purpose of enteral tube feeding? Explain the types of different enteral tube feeding methods (3). What are the indications and possible problems arose from it? What are the guidelines for its administration, especially for its use of syringes?

Answer 9

• For patients with functioning GI tract but inadequate/unsafe oral intake
• Through nose/abdominal wall, categorised into nasogastric (NG) or nasojejunal (NJ) fine bore tube: for up to 6 weeks
• Percutaneous endoscopic gastrostomy (PEG) or percutaneous endoscopic jejunostomy (PEJ): for over 6 weeks
• Indications: dysphagia, severe intestinal malabsorption, increased nutritional requirements, eating disorders, self neglect, chronic vomiting diarrhoea
• Problems: diarrhoea, regurgitation, taste, abdominal distension, blocked tubing, pump problems, placement of external, dislocation of tubes (NG)
• Administration: use liquid preparation, follow online guidelines
• *Syringes should be of different colour and marked oral/enteral/IV (mistakes can cause death)

Question 10

What is the purpose of total parenteral nutrition (TPN)? State the different short-term and long-term indications for TPN. How is administered and the choice of PN decided? What are the components in a TPN bag? State the complications that may arise.

Answer 10

• For non-functional/inaccessible/perforated GI tract, gut failure
• Short-term indications: awaiting feeding tubes, bowel obstruction, following major excisional surgery, ICU patients with MOF, some IBD patients, severe pancreatitis, preterm neonates
• Long-term indications: radiation enteritis, Crohn’s disease following multiple resections, motility disorders, bowel infarction, cancer surgery
• Administration: infusion over 24 hours, into major vein due to high osmolality (intrajugular, subclavian), through peripherally inserted central catheter (PICC) or Hickman Line
• Choice of PN: decided by MDT team, build up calories slowly, nutritionally complete in all-in-one mixtures, tailor made bags, in Aseptic Pharmacy Departments/Suppliers
• Components of TPN bag: nitrogen (protein), glucose, fat, fluid, vitamins, minerals
• Complications: air embolism, catheter blockage, line infections, metabolic problems, bone disease, refeeding syndrome (drastic shift)