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Nutritional Assessment- how to do it.
April 2011Dr Alan Stewart MB BS MRCP
www.stewartnutrition.co.uk
Nutritional Assessment
“..all doctors should be able to diagnose nutritional deficiencies.”
Royal College of Physicians 2002
Nutritional Assessment: What You Will Learn
1. How nutritional deficiencies develop
2. What are the common causes and effects of deficiency
3. The three key stages in Nutritional Assessment:- history- examination- investigation
4. A simple method of dietary assessment
5. The prevalence of nutritional deficiencies in the UK according to the National Diet and Nutrition Surveys
6. The importance of Nutritional Assessment
Types of Essential Nutrients
Macronutrients
• Energy - provided by Carbohydrates, Fats, Protein and Alcohol• Protein – Essential and non-essential amino acid
Micronutrients• Minerals: Bulk Ca, Mg, Na, K, Cl, P
Trace Fe, Zn, Cu, Mn, I, Se, ? others
• Vitamins: Fat-soluble A,D,E, and KWater-soluble B group and C
• Essential Fatty Acids: n-3 seriesn-6 series
Development of a Nutritional DeficiencyDeficiencies evolve through five stages: • Adequacy
• State of Negative Balance
• Decline in Tissue Stores
• Loss of Function
• Death
How was this arrived at?
Experimental Thiamine DeficiencyBrin M. Journal of the American Medical Association 1964;187:762-766
• Group of students volunteered for a 6 week study• Normal diet but deficient in thiamin (<200ug/day, EAR 1000 ug)• Test erythrocyte thiamin pyrophosphate TPP Effect – measures
increase in enzyme activity when thiamin is added to blood sample
Time in days
Clinical Picture TPP Effect
Dr Brin’s Term
5 None. Intake<Requirement <1.1 Preliminary
10 -20 Fall in blood and urine levels >1.1 Biochemical
21- 28 Fatigue, loss of appetite, nausea, insomnia, calf pain, anxiety
1.2 Physiological
30 Ankle swelling, cardiac enlargement, significant weight loss
1.35 Clinical
>30-300 Cardiac failure, loss of balance/co-ordination, mental decline
Est 1.5 Anatomical
How Do Nutritional Deficiencies Develop?Adapted from Brin M 1964
Develop over days to years in a logical and recognizable sequence
• State of Adequacy
• State of Negative Balance
• Decline in Tissue Stores
• Loss of Function:1. Symptoms 2. Physical Signs3. Organ Failure
• Death
Development of a Nutritional Deficiency
• Adequacy
• State of Negative Balance:1. Poor Intake
2. Reduced Absorption
3. Increased Losses4. Increased Demand5. Altered Metabolism
• Decline in Tissue Stores
• Loss of Function:1. Symptoms 2. Physical Signs3. Organ Failure
• Death
• This sequence evolves over:weeks (vitamin B1), months (zinc) or years (calcium and vit. B12)
• The causes of negative balance can be assessed or suspected from the history
• Tests will assess tissue levels, but not all deficiencies are clinically significant
• Nutritional deficiencies are most common at the extremes of age and some deterioration in nutritional state is a normal part of ageing
• More people will have mild symptoms of deficiency than physical signs or complete loss of function and organ failure
• The clinical picture of deficiency will depend on the loss of life function
Life Functions and Nutritional Deficiency
Life Functions Dysfunction caused by Deficiency
• Movement Bone Fracture, Muscle Weakness
• Respiration Early Muscle Fatigue
• Sensitivity Neuropathy, Blindness, Reduced Intelligence
• Nutrition Reduced ability to obtain food and feed self
• Excretion Liver/Renal Disease
• Reproduction Infertility, Miscarriage, Small-for-date Babies
• Growth Infant Stunting
• Defence Recurrent or Severe Infection
Three Methods of Nutritional Assessment
1. History
2. Physical Examination
3. Laboratory Investigation
The National Diet and Nutrition Surveys• Four surveys covering ages 1.5 yrs to >85 yrs
• Random samples of the British population with approximately 2,000 subjects in each
• Field-work conducted between 1990 and 2001
• Collected information on: - 4-7 day weighed dietary intakes- laboratory measures of nutrients- alcohol intake, supplement use- BP and BMI
• No assessment of symptoms or signs of deficiency
• The surveys provide useful information about the prevalence of nutritional deficiencies and the associated risk factors
The Prevalence of Anaemia: NDNS
0%
5%
10%
15%
20%
25%
30%
1.5-2.5yr 4-6yr 15-18yr 35-49yr 75-84yr Institution85+yr
Male
Female
• World Health Organisation Normal Ranges; 1.5-6.0 yrs >11.0g/dl, adult women >12.0g/dl, adult men >13.0g/dl.
• Adult ranges have been adopted from ages 15yrs and upward• British laboratories often use a normal range of >11.5g/dl for adult women• Levels of 11.5-11.9g/dl in women can result in symptomatic iron deficiency
Three Methods of Nutritional Assessment
1. History Intake: diet + supplements Risk Factors for deficiencySymptoms of deficiency
2. Physical Anthropometric MeasuresExamination (Body Mass Index - kg/m2)
Signs of Deficiency Signs of Underlying
Disease
3. Laboratory Blood and Urine TestsInvestigation Bone Mineral Density X-Ray
Medical Diagnosis: History is the Most Important
Nottingham 1975 W. Virginia 1992
History 82.5% 76%
Examination 8.75% 12%
Investigation 8.75% 11%
• Both studies assessed new patients, with no clear diagnosis who were referred to a medical clinic, to determine what information was required to reach the final diagnosis
• Hampton JR et al. BMJ. 1975;2:486-9• Peterson MC et al. West Med J. 1992;156(2):163-5
History: Dietary Assessment - Introduction
• Not as easy (or as quick & accurate) as you might think.
• Two separate questions: Is the diet healthy?Is the diet adequate?
• World Health Organisation and UK Food Standards Agency set simple but varying targets for “healthy eating”.
• Formal dietary assessment for adequacy involves:- prospective diet diaries for several days and - computerised analysis of macro/micronutrient intakes.
• Simple assessment is needed for use in a clinic setting
• Knowledge of the prevalence of deficiency (poor intakes and sub-normal test results) in the British population: National Diet and Nutrition Surveys, NDNS (1990-2003)
Healthy Eating Guidelines
Food Standards Agency 2006
• Base your meals on starchy foods
• Eat appropriately for your weight
• Fruit and Vegetables >5 portions/day
• Salt <6 g/day
• Sugar: limit intake if overweight
• Saturated fats: limit intake
• Alcohol: Weekly targets of: <21 units for men
<14 units for women
• Breakfast: eating it regularly helps adherence to a healthy diet and weight loss programme
World Health Organisation 2008
• Eat appropriately for your weight
• Fruit and Vegetables: have a good daily intake of fresh varieties
• Salt <5 g/day
• Sugar: limit intake of free sugars such as sucrose, fructose and glucose
• Saturated fats: limit intake of saturated fats which are derived mainly from animal foods andsome tropical oils
Healthy Eating: EU Guidelines 2008
• Recommendations made by each country for:
- Protein-rich foods: lean meat and poultry, legumes and fish
- Dairy foods: milk/yoghurt and cheese
- Carbohydrate-rich foods: wholegrain cereals, potato and rice
- Fruit and Vegetables
• Much agreement and some disagreement
• These food groups provide approximately 2/3rds of essential micronutrients in the British adult diet
• If an individual achieves good targets for each group then nutritional inadequacy due to poor intake is very unlikely
• References: Working Document on Setting Nutrient Profiles 21/10/2008 www.food.gov.uk/multimedia/pdfs/consultation/ecsettingnp.pdf
Dietary Assessment: 6 Simple Targets for AdultsTargets are adapted by the author from various sources
Food Category Target
Protein-rich foods >1 good portion every day
Fish* >2 Portions/week including >1 Oily type/week
Dairy Foods or Soya >1.5-2 Portions/day
Fruit and Vegetables* >5 Portions/day
Quality Carbohydrate >1-4 Portions/day
and
Alcohol (men/women)* <21/14 units/week
* Target set by UK Food Standards AgencyOther targets based on commonsense and other EU countries’ guidelinesSeparate assessments need to be made for fats, sugar and salt
Quality Carbohydrate vs. Starchy Foods
• The UK FSA advises “base your meals on starchy foods”
• This advice does not address the problems of poor intakes of vitamin C, folate and fibre or emphasise the benefits of wholegrain and fibre-rich foods in reducing heart disease and cancer
• Better advice is to recommend Quality Carbohydrates:wholegrain breakfast cereals from wheat, oats and otherswholemeal, granary and wheatmeal breads and chappatiwholemeal pastabrown ricefresh potatoes with their skins
• Emphasising these foods as opposed to white pasta and white rice will improve nutrient intake for many in the UK
• The number of daily portions, typically 1-4 per day, depends on physical activity and weight
Main Food Groups: Nutrients Provided
Food Group Main Nutrients Provided or
Nutritional ConsequencesProtein-Rich Foods Protein, Iron, Zinc, vitamin B complex including
B12 and vitamin A if liver is consumed
Fish and Oily Fish Protein, n-3 Essential Fatty Acids, vitamins B12 and D, and Iodine
Dairy Foods Protein, Calcium, Iodine, Vitamin A – retinol, Vitamins B2 and B12
Fruit and Vegetables Potassium, Vitamin C, Folate, beta-carotene and Fibre. Iron absorption is greatly enhanced
Quality Carbohydrates Potassium, Magnesium, Copper, B vitamins but not B12, and Fibre. Vitamin C from potato
Alcohol (to Excess) Adverse effect on virtually all nutrients except iron. Vitamin B, Zinc and Calcium deficiencies
Estimated Provision of Micronutrients by Major Food GroupsPercentages of Total Dietary Provision
Author’s estimated from NDNS of British Adults: Data collected 2000/1
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Calcium Iron Zinc Folic A Vit B12 Vit C
ProteinFishDairyFrt & VegQual CHOTotal
Estimated Provision of Micronutrients by Major Food GroupsTotals from: Proteins, Fish, Dairy Foods, Fruit and Vegetables and Quality Carbohydrates
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Prot Ca Mg K Fe Zn Cu I Vit A Vit C Vit B1 Vit B2 Folate VitB12
n-3EFAs
Adults 19-64 yrs NDNS
Prevalence of Poor Eating Habits in British AdultsAuthor’s Estimates from National Diet and Nutrition Survey 2000/1 aged 19 to 64 years
of failure to achieve 6 Healthy Eating Targets
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Protein Fish andOily Fish
DairyFoods
Fruit andVeg
QualityCarbs
Alcohol
Men
Women
Defining Inadequate Nutritional Intake
• Nutritional deficiency can develop from a prolonged low intake
• UK nutrient intake requirements are set out in the report:Dietary Reference Values for Food Energy and Nutrients for the United Kingdom (1991 – TSO)
• The report defines The Lower Reference Nutrient Intake, LRNI, for protein or a vitamin or mineral as “An amount of the nutrient that is enough for only a few people in a group who have low needs”.
• In practice this means that if the percentage of a population with an intake below the LRNI for a particular nutrient exceeds 3% then it is likely that a significant percentage of the population will be deficient in the nutrient
NDNS: Prevalence of Deficiency - Low IntakeTotal Intakes (Food and Supplements) below LRNI for males and females
0%
3%
6%
9%
12%
15%
18%
21%
24%
27%
30%
33%
36%
39%
Infants Children Adults Free-livingElderly
InstitutionElderly
Calcium
Potassium
Magnesium
Iron
Zinc
Vitamin A
Vitamin B12
Folate
Vitamin C
• “Lower Reference Nutrient Intake – an amount of the nutrient that is enough for only the few people in a group who have low needs”. Considered to be <3% of the population
• Prevalence rates >3% suggest that a significant percentage of the population could be deficient• Low iron intakes are observed in 33% of adult women of menstruating age
History: Dietary Assessment - Conclusions• Formal dietary assessment is useful but time consuming
• Assess the healthfulness of a person’s diet by asking about intake of: protein-rich foods, fish/oily fish, dairy foods, fruit and vegetables, quality carbohydrates and alcohol
• These groups encompass 2/3rds of micronutrient intake
• Failure to achieve a good standard for these food groups will alert the practitioner to a possibly inadequate intake
• Separate assessments need to be made for salt, sugar and fats
• Assess intake from nutritional supplements and be aware of possibly excessive intake
Nutritional Assessment - Risk FactorsNICE guidelines www.nice.org.uk/cg032 (2006) and others
• Fragile skin• Poor wound healing• Apathy• Wasted muscles• Poor appetite• Altered taste sensation• Impaired swallowing• Altered bowel habit• Loose fitting clothes• Prolonged intercurrent illness:
chronic infection, chest disease, cardiac failure, cancer etc.
• Extremes of age• Receiving benefits• Living alone – especially men• Alcohol, tea, coffee in excess• Reduced mobility • Lack of sun exposure• Some drugs and multiple therapy• Heavy periods• History of miscarriage• Recovery from illness/operation• Pregnant or breastfeeding• Family history/genetic factors• Smoking• Inappropriate use of supplements
Nutritional Support in Adults [www.nice.org.uk/CG032 February 2006]
Screen all patients to identify those most at risk of being deficient:
• UnderweightA body mass index (BMI) of less than 18.5kg/m2
• Unintentional weight lossGreater than 10% within the last 3 – 6 months or
• Combination of:BMI of less than 20kg/m2 andUnintentional weight loss greater than 5% within the last 3 – 6 months
Others at risk:• Those who have eaten little or nothing for more than 5 days and/or
are likely to eat little or nothing for 5 days or longer• Those with a poor absorptive capacity and/or high nutrient losses and/or
increased nutritional needs from causes such as catabolism• Those already identified with one deficiency e.g. anaemia or osteoporosis
Prevalence of Underweight BMI <18.5 kg/m2
Adults aged 16 years and older in England, 2006. NHS Information Centre
0.00%
1.00%
2.00%
3.00%
4.00%
5.00%
6.00%
7.00%
8.00%
9.00%
10.00%
All 16-24 25-34 35-44 45-54 55-64 65-74 75+
Men
Women
Benefit Status and Micronutrient IntakePercentage of Male Population 19-64 yrs with deficient intake, <LRNI*
0%3%6%9%
12%15%18%21%24%27%30%33%36%39%42%45%48%51%
Vit A B1 B2 B3 B6 B12 Fol Vit C Fe Ca P Mg K Zn I
Men No Benefits n=724
Men Benefits n=110
• Data from National Diet and Nutrition Survey British Adults. TSO 2003/4• <Lower Reference Nutrient Intakes are likely to be adequate for <3% of the population.
Ref: Dietary Reference Values for Food Energy and Nutrient for the UK. HMSO 1991
Benefit Status and Micronutrient IntakePercentage of Female Population 19-64 yrs with deficient intake, <LRNI*
0%3%6%9%
12%15%18%21%24%27%30%33%36%39%42%45%48%51%
Vit A B1 B2 B3 B6 B12 Fol Vit C Fe Ca P Mg K Zn I
Women No Benefits n=741
Women Benefits n=150
• Data from National Diet and Nutrition Survey British Adults. TSO 2003/4• <Lower Reference Nutrient Intake are likely to be adequate for <3% of the population.
Ref: Dietary Reference Values for Food Energy and Nutrient for the UK. HMSO 1991
Influence of Household Income on Average Intake of Nutrients in Elderly Men [NDNS 1998]
0%
20%
40%
60%
80%
100%
120%
140%
160%
Energy Protein Vitamin C VitaminB12
Folate
<4K/yr
4-6K/yr
6-10K/yr
>10K/yr
• Annual income in £000s; upper income bands are compared with lowest <4k/year• Increasing income is associated with higher intake of protein and many nutrients
Educational Attainment and Nutrient Intake (LIDNS):% less intake if education < 5 GCSE grades A-C or equivalent
-25%
-20%
-15%
-10%
-5%
0%
Energy Protein Folate Potassium Magnes'm Copper Zinc
Males
Females
• In males energy difference significant p <0.031; all other nutrients p <0.004• In females all nutrients difference significant p <0.009
Dental Health and Nutrient Intake (LIDNS):% difference in intake if edentate compared with dentate
-35.00%
-25.00%
-15.00%
-5.00%
5.00%
15.00%
25.00%
35.00%
Energy Protein NSP NMES Vitamin C Iron
Males 50-64yrs
Males 65+ yrs
Females 50-64 yrs
Females 65+ yrs
• NSP Non-starch polysaccharides; NMES Non-milk extrinsic sugars• No data on differences in intake of potassium, magnesium or folate were
presented but are likely to be similar b to but less than those for vitamin C• Data on younger age groups were not presented
Daily Alcohol Intake and Nutritional Status: NDNS 65+% difference in status compared with non/low drinkers
-30.00%
-20.00%
-10.00%
0.00%
10.00%
20.00%
30.00%
40.00%
50.00%
PlasmaVitamin C
PlasmaVitamin D
Red CellFolate
SerumVitamin B12
Males <10g
Males 10-20g
Males =/>20g
Females <10g
Females =/>10g
• Intake determined from 4 day diary • Caution, no adjustment for age, health, diet or supplements was made• Non-drinkers were more likely to be older and have abnormal liver test
History: Symptoms of Nutritional Deficiency
• Specific SymptomsDelayed dark adaption - vitamin A or zincSore tongue - iron, vitamin B12 and other B vitamins
• Non-specific Symptoms* Fatigue - anaemia, iron, potassium, magnesium,
vitamins B and CCold intolerance - ironLoss of appetite - iron, vitamin B group and zincPoor immunity - protein, zinc, vitamins A and BMenstrual irregularity - protein, vitamin B12 and other nutrientsMuscle cramps and pain - potassium, magnesium and vitamin B1Numbness in feet/hands - vitamins B1, 3 and B12Mood change - vitamins C, B, folic acid and magnesiumCognitive decline - vitamins B12, B1 and B3, and
n-3 essential fatty acids
* Symptoms may often be due to non-nutritional causes
Examination: Signs of Nutritional Deficiency
• Mouth Mouth Ulcers – ironCracking at corners of mouth – iron, vitamin B
• Skin Dry scaley skin – Essential Fatty AcidsEasy bruising – vitamin C
• Hair Scalp hair loss – iron• Nails Spoon-shaped nails - iron• Skeleton Spinal curvature – calcium and vitamin D
Low impact fracture – calcium and vitamin D• Muscle Calf muscle tenderness – vitamin B1
Loss of strength – potassium, magnesiumWeak hip muscles – vitamin D
• Eyes Clouding of the cornea – vitamin A• Neurological Loss of sensation in hands and feet – vitamins
B1, B12Loss of vibration sense – vitamin B12
• All the above signs also have non-nutritional causes
Investigation: Laboratory Tests of Nutritional Status
• GP TestsFull Blood Count red and white cells, plateletsSerum Ferritin or Serum Iron, Total Iron Binding Capacity + % satSerum Vit B12 and serum or Red Cell FolatePlasma Na, K, vitamin DBone Mineral Density (Ca)
• Other TestsPlasma elements: Zn, Cu, Se, Mn, MgRed cell magnesiumVitamins B1, B2 and B6 – enzyme activationPlasma retinol, plasma or WBC vitamin CUrine Na, K, Iodine
• Specialised and Rare TestsPlasma Homocysteine, MMA, Holo-transcobalamin, Enzyme testsX-rays (vitamin D and C), Brain MRI (Mn)Tissue levels – bone marrow, liver biopsy, post-mortem
Test Choice
Negative BalancePoor Intake etc.
Risk Factor:Medical or
SocialPhysical Sign
The Prevalence of Anaemia: NDNS
0%
5%
10%
15%
20%
25%
30%
1.5-2.5yr 4-6yr 15-18yr 35-49yr 75-84yr Institution85+yr
Male
Female
• World Health Organisation Normal Ranges; 1.5-6.0 yrs >11.0g/dl, adult women >12.0g/dl, adult men >13.0g/dl.
• Adult ranges have been adopted from ages 15yrs and upward• British laboratories often use a normal range of >11.5g/dl for adult women• Levels of 11.5-11.9g/dl in women can result in symptomatic iron deficiency
Prevalence of Iron Deficiency: NDNSLow Plasma Ferritin: Range < 10-20ug/l
0%
5%
10%
15%
20%
25%
30%
1.5-2.5yr 4-6yr 15-18yr 35-49yr 75-84yr Inst 85+yr
Male
Female
• Normal ranges: infants age 1.5-4.5yrs > 10.0ug/l, females age >4yrs-adult > 15.0ug/l, males age >4yrs-adult > 20.0ug/l
• Plasma ferritin can be elevated by acute or chronic inflammation, infection or liver disease and is not a reliable measure of iron status in ill and elderly people
Prevalence of Vitamin B12 Deficiency: NDNS Plasma <118 pmol/l
0%
5%
10%
15%
20%
25%
30%
1.5-2.5yr 4-6yr 15-18yr 35-49yr 75-84yr Institution85+yr
Male
Female
• A serum vitamin B12 of 118pmol/l is equivalent to 154pg/ml• Macrocytosis (MCV >101fl) was seen in: 1-3% of teenagers, 9% of adults,
2% of free-living elderly and 3% of elderly in institutions. • Macrocytosis is often due to alcohol excess and not vitamin B12 deficiency
Prevalence of low Red Cell Folate: NDNS
0%
5%
10%
15%
20%
25%
30%
35%
40%
45%
50%
1.5-2.5yr 4-6yr 15-18yr 35-49yr 75-84yr Institution85+yr
MaleFemale
• The normal ranges for red cell folate and method of analysis varied with each study;infants > 400nmol/l, children and adults > 350nmol/l and the elderly > 345nmol/l
• Folate status is influenced by alcohol excess and altered metabolism in the elderly• Pregnant or breast feeding women were excluded from the adult NDNS
Prevalence of Vitamin C Deficiencyplasma Vit. C<11.0umol/l - NDNS data
0%
10%
20%
30%
40%
50%
60%
1.5-3.5yr
2.5-4.5yr
4-6yr 7-10yr 11-14yr
15-18yr
19-24yr
25-34yr
35-49yr
50-64yr
65-74yr
75-84yr
85+yr Inst65-
84yr
Inst85+yr
Male
Female
• Approx. 20% of adults and 12% of the elderly took supplements of vitamin C• Approx. 25% of British adults smoke and this declines after the age of 65 years• Aspirin was taken by 20% of free-living elderly and 24% of institutionalised elderly
Nutritional Deficiencies in Acutely ill Geriatric Patients: Prevalence of Haematological Deficiencies 1973/75
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Anaemia RBC Folate Vitamin B12 % Iron Sat
Age 65-70yrs (n=16)
70-79yrs (n=53)
80+yrs (n=24)
• 93 acutely ill patients >65yrs: male = 35, female = 58 in Yorkshire• Folate and vitamin B12 were measured using micobiological assays• 9/93 = plasma albumin >28g/l, 29/93 = plasma albumin 28-34g/l• Refs: Morgan AG et al. Int J Vit and Nut Research. 1973:43;46-471 & 1975:45:448-462
Vitamin Deficiencies in Acutely ill Geriatric Patients:
Prevalence of various vitamin deficiencies 1973/75
0%
10%
20%
30%
40%
50%
60%
70%
80%
90%
100%
Vit A PTT TPP Vit B2 Vit B3 WBC Vit C
Age 65-70yrs (n=16)
70-79yrs (n=53)
80+yrs (n=24)
• 93 acutely ill patients >65yrs: male = 35, female = 58• PTT = prothrombin time (Vit K), TPP = thiamin pyrophosphate effect (vit B1)
Vit B2 = whole blood riboflavin, Vit B3 = urine n-methyl nicotinamide level• References: Morgan AG et al. Int J Vit and Nut Research. 1975:45:448-462
Vitamin B Deficiencies in Newly-Admitted Psychiatric Patients [Middlesex 1970s]
0%
10%20%
30%40%
50%
60%70%
80%90%
100%
Alc/DrugAbuse
Schizo -phrenia
EndogDepress
Mania NeurotDepress
Neurosis OrganicPsychosis
Total
Vitamin B1
Vitamin B6
• 154 Acute psychiatric patients with a history of poor diet: male = 52, female = 102• Vit. B1 Def = Serum Pyruvate >79umol/l (n=154), Trans Ketolase AC > 1.3 (n=74)• Vitamin B6 deficiency = Aspartate Transaminase Activation Coefficient > 1.75 (n=66)• Reference: Carney MWP et al. British Journal of Psychiatry 1979;135: 249-54
Investigation: Interpreting Nutritional Tests
• There are numerous tests of nutritional status• An abnormally low result does not always mean that there is a significant
deficiency• There are essentially two types of tests:
- tests that measure the level of a nutrient- tests that measure the function of the nutrient
• Tests that measure the level of a nutrient are:serum vitamin B12serum ferritin (iron)serum retinol
• Corresponding test that measure the nutrient’s function are:serum methylmalonic acid MMA (vitamin B12)haemoglobin leveldark adaption test
• Occasionally high levels of a nutrient are found • Test results must always be interpreted with knowledge of the full clinical
picture of findings from history and examination
Nutritional Assessment: Clinical Summary
• Ask about diet: type of diet and consumption of major food groups
• Ask about use of supplements
• Assess risk factors: medical – unintentional weight loss, feeding difficultiesnon-medical – socioeconomic
• Ask about symptoms of possible deficiency
• Measure BMI and examine for signs of possible deficiency
• Decide upon appropriate tests of nutritional state
• Interpret data from:history, examination and investigation carefully
• Treat the deficiency (diet and nutrition support) and underlying causative factors
• Monitor response to treatment
Treatment Plan
Correct Undernutrition
Treat Underlying Disease
or Cause
Add inFortified Foods
Use Nutritional Supplements
Improve/ChangeFood Intake
Nutritional Assessment: The Gold Standard
“..all doctors should be able to diagnose nutritional deficiencies.”
Royal College of Physicians 2002
Remember the Final Test of a Deficiency is if ..
Nutritional Assessment: Key References
You have covered
• Nutrition is one of the essential functions of life
• What are the essential nutrients?
• How do we know a nutrient is essential?
• How do nutritional deficiencies develop?
• An outline of nutrition assessment
• What are the common nutritional problems?
References and Further Information
Nutritional Assessment
End of Presentation
Dr Alan Stewart MB BS MRCP
www.stewartnutrition.co.uk
Nutritional Assessment: The End
Thank you for your attention
If you would like to be sent the four page handout that accompanies this lecture or would like me to deliver the full illustrated version of this presentation please email me at
[email protected] 01273-487003
For additional lectures see related presentations on: National Diet and Nutrition SurveysHow Safe are Nutritional Supplements? at www.stewartnutrition.co.uk
