GeriQBank · Paper III · Q10
Vitamin deficiencies in the elderly
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- Gastroenterology & Nutrition
- Years asked
- Not recorded in the source
- Frequency
- Set 1× in Paper III (2009–2025)
As set in the university paper
Vitamin deficiencies.
Paper III · Gastroenterology & Nutrition · asked ×1 · 7-mark note · see in paper list
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Vitamin deficiencies in the elderly
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General Principles
Vitamins and minerals are micronutrients — required in minute quantities but essential for life, functioning as hormones, antioxidants, enzyme cofactors, and in one-carbon metabolism and DNA synthesis. They cannot be synthesised in adequate quantity and must come from food, fortified food or supplements.
Classification: water-soluble (B group and vitamin C) and fat-soluble (A, D, E, K). Fat-soluble deficiency accompanies fat malabsorption; water-soluble deficiency develops faster because stores are small.
Pathy's makes the important point that the same age-associated changes in food intake that cause protein-calorie inadequacy also cause multiple micronutrient deficiencies, and that inadequate intake can impair cellular and physiological function even before a classic deficiency syndrome appears.
Causes in older adults: anorexia of ageing, reduced taste and smell, poor dentition, dysphagia, poverty and isolation, chronic disease, malabsorption, alcohol, and polypharmacy with drug–nutrient interaction.
Nutrients of public health concern for older adults (Pathy's): the vitamins choline, riboflavin, thiamine, A, C, D and E, and the minerals calcium, magnesium, potassium and selenium.
Essentials adds a corrective: there is no general increase in vitamin requirements with age — requirements for vitamins A, B1, B2, C, B6 and B12 do not rise with age. What changes is intake and absorption, not requirement.
Vitamin B12 (Cobalamin)
Prevalence rises with age, ranging from 5% to 40% depending on the cut-off used. In one Canadian nursing home study of 412 residents, prevalence was 13.8% on admission with a new incidence of 4% per year.
Causes: food-bound B12 malabsorption from atrophic gastritis affects 10–30% of older adults; pernicious anaemia (lack of intrinsic factor) occurs in 1–2%; drugs — PPIs, H2 blockers and metformin; gastric or ileal resection; SIBO; and strict vegetarian or vegan diets, since B12 is found only in animal products.
Features: macrocytic anaemia (which may be absent), plus fatigue, weakness, anorexia, weight loss, numbness and tingling, balance problems, depression, confusion, dementia, poor memory and glossitis. Subacute combined degeneration of the cord is the classic neurological syndrome.
Diagnosis: there is no gold standard test. Diagnosis rests on anaemia plus a low B12; methylmalonic acid and homocysteine are both raised and add sensitivity but are not mandatory.
Treatment: oral or intramuscular; oral is easier, cheaper and likely as effective at high enough doses. Recheck haemoglobin and B12 at 3 months. Because of malabsorption of food-bound B12, those aged 50 and over should meet the RDA mainly from fortified foods or a supplement.
Folate (Vitamin B9)
Causes: poor intake, alcoholism, malabsorption (folate is absorbed in the jejunum by passive transport), atrophic gastritis, smoking, and drugs — methotrexate, sulfasalazine, trimethoprim and phenytoin.
Stores are small, so deficiency develops in weeks to months, unlike B12.
Diagnosis: low haemoglobin, raised MCV, low serum folate, low reticulocyte count. Serum folate <2 ng/mL is deficient, 2–4 ng/mL borderline, >4 ng/mL normal. In folate deficiency MMA is normal and homocysteine is raised, in contrast to B12 deficiency where both are raised. Red cell folate reflects status over the preceding 120 days.
Treatment: folic acid 1 mg daily orally. Always correct B12 first — giving folate alone in B12 deficiency can precipitate or worsen neurological damage. Correcting B12 may resolve a relative folate deficiency without supplementation.
Vitamin D
Mechanism of deficiency in the elderly: limited sunlight exposure plus a fourfold reduction in the skin's capacity to produce vitamin D, compounded by reduced intestinal absorption with age.
Prevalence: in the relatively healthy older Europeans of the SENECA study, 40% had serum 25(OH)D below 30 nmol/L — itself below the proposed adequacy threshold of at least 50 nmol/L.
Recommended intakes after age 50 (Pathy's): calcium 1000–1200 mg/day and vitamin D 800 IU (20 µg)/day; upper limits are 2000 mg for calcium and 4000 IU (100 µg) for vitamin D.
Assessment and treatment: status is assessed by serum 25(OH)D; at a minimum, concentrations below 25–30 nmol/L (10–12 ng/mL) should be treated. Essentials adds that nursing home residents require at least 800 IU daily — double the usual recommendation — to maintain normal levels.
Benefits: supplementation reduces bone loss and fracture rate in both older men and women, and more recent trials indicate improvement in sarcopenia and a decrease in falls.
Other Vitamins and Key Minerals
Thiamine (B1): deficiency in alcohol misuse, poor intake, refeeding and diuretic use; causes wet and dry beriberi and Wernicke's encephalopathy. Must be given before dextrose in any at-risk patient.
Vitamin B6 (pyridoxine): dietary deficiency is rare and usually occurs with other water-soluble vitamin deficiencies; causes include alcoholism, malabsorption, dialysis and drugs acting as pyridoxine antagonists (isoniazid). Assessed by plasma pyridoxal-5-phosphate.
Riboflavin (B2): contributes to hyperhomocysteinaemia; not usually high-risk in those consuming adequate dairy.
Hyperhomocysteinaemia: inadequate B2, B6, folate or B12 raises homocysteine, an independent cardiovascular risk factor also correlated prospectively with dementia and osteoporotic fracture. Folate lowers homocysteine most effectively — but Pathy's is explicit that homocysteine-lowering B vitamins have been mostly unsuccessful in reducing incidence of cardiovascular disease, osteoporosis or Alzheimer's progression.
Vitamin C: readily lost from food during storage and preparation — losses may account for about 50% of the potential dietary content, and around 30% of subjects in European studies had inadequate intake. Absorption is not affected by age. Deficiency causes scurvy — perifollicular haemorrhage, gum bleeding, poor wound healing.
Vitamin K: deficiency from fat malabsorption, prolonged antibiotics and poor intake; causes prolonged prothrombin time and bruising. Note the interaction with warfarin in both directions.
Vitamin A: deficiency causes night blindness and xerophthalmia; note that vitamin A absorption increases with age, so excess is as relevant a hazard as deficiency in supplemented older adults.
Zinc: deficiency is seen in older people, particularly in diabetics; causes anorexia through impaired taste and smell, impaired vision, confusion and restlessness, sometimes diarrhoea, and reduced immunity, collagen synthesis and wound healing. Cytokines dramatically reduce serum zinc, so plasma levels are unreliable in illness — leucocyte or hair zinc may be more useful.
Iron: less prevalent in older than younger people; requirement falls sharply after the menopause. Distinguish iron deficiency from anaemia of chronic disease using ferritin and CRP. When anaemia is diagnosed, chronic blood loss or folate/B12 deficiency must be considered.
Overall caution from Pathy's: beyond general health, the role of each micronutrient in preventing or treating specific chronic disease is unclear from clinical trial data; given limited efficacy and potential adverse effects, supplements should be chosen to contain no more than the recommended amounts (about 100% of recommendations).
Latest Updates (2023–Present)
The Endocrine Society Clinical Practice Guideline on vitamin D (2024) represents the biggest shift. It suggests empiric supplementation for the general population aged 75 and over to lower mortality risk, but suggests against routine 25(OH)D testing in all populations considered, including those aged 75 and over (J Clin Endocrinol Metab, 2024).
The same guideline advises against empiric supplementation above the DRI in healthy adults under 75, and for people over 50 with an indication, recommends daily lower-dose vitamin D rather than intermittent high doses. Trial doses informing the mortality recommendation ranged from 400 to 3333 IU daily, with a weighted average of about 900 IU daily (J Clin Endocrinol Metab, 2024).
Critically, the Endocrine Society no longer endorses 30 ng/mL as a sufficiency target, and states no clear evidence defines an optimal 25(OH)D level for disease prevention — a reversal of its own 2011 position that remains contested by other experts (J Clin Endocrinol Metab 2024; Endocr Pract commentary 2024–2026). Note the scope limitation for exams: this guideline addresses disease prevention in generally healthy people without established indications for testing or treatment. It does not apply to patients with malabsorption, CKD, osteoporosis, osteomalacia or drug-induced deficiency, where testing and treatment remain fully indicated (J Clin Endocrinol Metab, 2024).
The UEG 2025 malabsorption guideline stresses that screening for B12 in the elderly is important because some related neurological abnormalities reverse with supplementation, and identifies chronic PPI use and SIBO as aggravating factors alongside atrophic gastritis (United European Gastroenterol J, 2025). The USPSTF continues to recommend against vitamin D with or without calcium for primary fracture prevention in community-dwelling postmenopausal women and men aged 60 and over — consistent with the 2024 guideline's restraint (USPSTF, reaffirmed in JBMR commentary 2025).
Current Practice Update
Textbook position (Pathy's / Essentials) Current evidence (2023–2026)
Assess vitamin D status by 25(OH)D; treat levels below Endocrine Society 2024 suggests against routine 25(OH)D testing 25–30 nmol/L; adequacy often taken as ≥50 nmol/L. in generally healthy people and no longer endorses a numerical sufficiency target. Testing remains indicated in malabsorption, CKD, osteoporosis and osteomalacia.
800 IU vitamin D daily recommended after age 50; Empiric supplementation now recommended specifically from nursing home residents need at least 800 IU. age 75 to reduce mortality, with daily low-dose preferred over intermittent high-dose in those over 50 — supporting the textbook dose but sharpening the age threshold and the regimen.
Homocysteine-lowering B vitamins mostly unsuccessful Position unchanged — no new trial has overturned it; treat for CVD, osteoporosis and Alzheimer's. documented deficiency, not the homocysteine number. B12 deficiency diagnosed on anaemia plus low B12, Unchanged, but UEG 2025 adds a stronger case for proactive B12 with MMA and homocysteine as adjuncts. screening in older adults, given reversibility of neurological features and the contribution of PPIs and SIBO.
Micronutrient supplements should contain no more Position reinforced; USPSTF continues to advise against routine than about 100% of recommendations. vitamin D and calcium for primary fracture prevention in community-dwelling older adults.
Examiner's Tip — mark-earning lines
"Requirements for most vitamins do not rise with age — what changes is intake and absorption." "10–30% of older adults malabsorb food-bound B12; pernicious anaemia accounts for only 1–2%." "MMA and homocysteine both raised in B12 deficiency; only homocysteine raised in folate deficiency." "Always correct B12 before folate — folate alone can worsen the neurological lesion." "Skin capacity to synthesise vitamin D falls fourfold in the elderly; 40% of healthy older Europeans in SENECA had 25(OH)D below 30 nmol/L."
"Homocysteine-lowering B vitamins have failed to reduce cardiovascular events, fractures or Alzheimer's progression."
Extra Points to Remember — Indian context
Vitamin D deficiency is highly prevalent across all Indian age groups despite abundant sunlight, driven by skin pigmentation, indoor living, covered clothing, air pollution and low dietary intake — so the Endocrine Society's "generally healthy Western population" caveats must be applied with care in Indian practice. B12 deficiency is common in Indian vegetarians irrespective of malabsorption — a lifelong dietary cause rather than an age-related one; combine dietary counselling with supplementation.
ICMR-NIN dietary guidelines for Indians provide the local RDA framework and should be quoted alongside Western figures.
Fortification programmes: India's fortified staples (double-fortified salt with iron and iodine, fortified oil and milk with vitamins A and D, fortified wheat flour and rice with iron, folic acid and B12) are the population-level answer. Practical Indian prescribing: cholecalciferol 60,000 IU weekly sachets are widely used for repletion followed by daily maintenance — but note the current preference for daily lower-dose regimens over intermittent high doses in those over 50.
Appendix — Rapid Revision Grid
NIGHT-BEFORE REVISION
Numbers Worth Quoting
Topic Figure
GORD prevalence 6th commonest disorder in residential care; ~20% of general population have weekly reflux; hiatus hernia in ~60% of those over 60 GORD diagnosis Heartburn/regurgitation ~70% sensitive; double-dose PPI trial 2–8 weeks, sensitivity and specificity up to 80% Constipation Faecal impaction in 7% of institutionalised elderly; median 42% prevalence in long-term care; 90% of slow-transit responds to laxatives; biofeedback effective in ~70% Laxative doses Psyllium 3–6 g; PEG 17–34 g; lactulose 10–40 g; senna 15 mg; bisacodyl 5–10 mg; sodium picosulfate 5–10 mg; lubiprostone 8–24 µg BD IBS in elderly 10–15% of people over 70; placebo response in functional GI disorders 20–70% Achalasia Perforation risk ~1% for both pneumatic dilatation and myotomy; series of 51 patients aged ≥65 — no deaths, median stay 3 days Gastroparesis Up to 80% of diabetic gastroparesis has abnormal small-intestinal motility; scleroderma oesophageal dysmotility ~80% UGI bleeding Bleeding contributes to ~5% of elderly deaths; GBS 0–1 for outpatient care; transfuse at Hb 7 g/dL (8 g/dL with CVD), target 7–9 g/dL; erythromycin 250 mg IV 30–120 min pre-scope; endoscopy within 24 h; high-dose PPI ×3 days then BD oral ×2 weeks Malabsorption Faecal fat >7 g/day; faecal elastase-1 <200 µg/g suggests, <100 µg/g severe EPI; SIBO antibiotics 1–4 weeks MNA Screening max 14 points: 12–14 normal, 8–11 at risk, 0–7 malnourished; sensitivity 96%, specificity 60%; mortality risk 0.35 (0.18–0.66) with normal score GLIM Weight loss >5% in 6 months or >10% beyond 6 months; needs 1 phenotypic + 1 etiologic criterion TPN 25–30 kcal/kg/day (20–25 if acutely ill/elderly); protein 1.0–1.5 g/kg/day; refeeding start 10–20 kcal/kg or 100–150 g dextrose in first 24 h, advance ~33% of goal every 1–2 days; thiamine 100 mg before dextrose Refeeding severity Fall from pre-feeding phosphate, magnesium or potassium: ≥10% mild, ≥25% moderate, ≥50% severe (ASPEN)
Vitamin B12 Prevalence 5–40%; 10–30% malabsorb food-bound B12; pernicious anaemia 1–2%; nursing home 13.8% on admission, 4%/year new Folate <2 ng/mL deficient, 2–4 borderline, >4 normal; treat with folic acid 1 mg/day; red cell folate reflects 120 days Vitamin D Calcium 1000–1200 mg/day and vitamin D 800 IU/day after 50; ULs 2000 mg and 4000 IU; treat 25(OH)D below 25–30 nmol/L; SENECA — 40% below 30 nmol/L; skin synthesis reduced fourfold Named Guidelines and Evidence by Topic Topic Named source Malabsorption UEG malabsorption guideline 2025; ACG coeliac guideline update 2023; ESsCD 2025 (no-biopsy pathway restricted to under-45s)
Constipation Joint AGA–ACG CIC guideline 2023 (first joint guideline; PEG, sodium picosulfate, linaclotide, plecanatide, prucalopride strong); ASCRS 2024 GORD Lyon Consensus 2.0 (Gut 2024); ACG GERD guideline 2022; AGA Clinical Practice Update on P-CABs 2024; VISION 5-year safety study 2025; Seoul Consensus focused update 2025 Motility Chicago Classification v4.0; ACG gastroparesis guideline 2022 UGI bleeding ACG UGIB guideline 2021; ESGE non-variceal 2021 and variceal 2022; ACG LGIB update 2023; restrictive transfusion meta-analysis (Sci Rep 2023)
Nutrition assessment GLIM consensus 2019 and 5-year update 2025; ESPEN geriatric nutrition and hydration guideline; ESPEN–EASO sarcopenic obesity consensus 2022; EWGSOP2 Parenteral nutrition ASPEN refeeding consensus 2020; ESPEN ICU guideline revision 2023; ASPEN PN ordering/compounding and CVAD standards Vitamins Endocrine Society vitamin D guideline 2024; USPSTF fracture prevention; ICMR-NIN dietary guidelines (India)
Classifications and Criteria to Name
Name Use
Rome IV Constipation, IBS, functional dyspepsia
Bristol Stool Form Scale Stool consistency; target type 4–5 in faecal incontinence Los Angeles classification A–D Erosive oesophagitis; only B, C, D conclusive for GORD under Lyon 2.0 Chicago Classification v4.0 Oesophageal manometry; achalasia types I, II, III Forrest classification Ulcer stigmata; treat Ia, Ib, IIa endoscopically Glasgow–Blatchford / Rockall Pre-endoscopic and post-endoscopic UGIB risk GLIM criteria Diagnosis of malnutrition — 1 phenotypic + 1 etiologic MNA / MNA-SF / SNAQ / MUST / NRS- Nutritional screening and assessment tools 2002 / SGA ASPEN refeeding criteria Grading refeeding syndrome by electrolyte fall Indian Context — One Line per Topic Malabsorption: tropical sprue, intestinal tuberculosis, giardiasis, strongyloidiasis and HIV enteropathy must appear in every differential.
Constipation: ispaghula (isabgol) is the accessible bulking agent; PEG sachets are affordable and preferable to repeated enemas at home.
GORD: pantoprazole and rabeprazole are the cheapest available PPIs; vonoprazan is marketed but cost-limited. UGI bleeding: variceal bleeding from cirrhosis, non-cirrhotic portal fibrosis and EHPVO is a major cause; PCC availability is variable outside tertiary centres, so FFP may be the practical alternative. Nutrition: LASI Wave 1 data document high rates of undernutrition among older Indians; NPHCE provides the service framework.
Vitamins: widespread vitamin D deficiency despite sunlight; B12 deficiency common in lifelong vegetarians; ICMR-NIN RDAs and national food fortification are the population-level responses.
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References
- PAPERS-2-3-4_COMBINED.pdf — page 835
- GeriQBank source PDF — p. 835
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