General pathology · Nutritional pathology
Vitamin deficiencies: what each one does to tissue !
- Topic
Each missing vitamin leaves its own mark: night blindness, soft bones, bleeding gums, nerve damage, rash or large red cells.
Updated 2026-11-01
What it is
Vitamins are cofactors and signals that tissues need to build collagen, bone, DNA and nerve. A deficiency comes from poor diet, malabsorption, alcohol use disorder, certain drugs or higher needs (pregnancy, growth). The lesions follow directly from what the vitamin does; the biochemistry is in the Bioquímica vitamin pages.
Key facts
- Vitamin A deficiency is a leading cause of preventable childhood blindness and raises measles mortality.
- Pellagra may appear in Hartnup disease, carcinoid syndrome and with isoniazid, besides poor diets based on maize.
- Excess of vitamin A is also harmful: raised intracranial pressure, liver injury and birth defects.
- Folic acid before conception prevents many neural tube defects.
Vitamin deficiencies and their tissue lesions
| Deficiency | Vitamin role | Tissue lesion |
|---|---|---|
| Vitamin A | Retinal pigment and epithelial differentiation | Night blindness, xerophthalmia, Bitot spots, keratomalacia, squamous metaplasia of airway and urinary epithelium, poor immunity |
| Vitamin D | Calcium and phosphate absorption, bone mineralisation | Rickets in children (bowed legs, rachitic rosary, craniotabes); osteomalacia in adults |
| Vitamin C | Hydroxylation of proline and lysine in collagen | Scurvy: bleeding gums, perifollicular haemorrhages, corkscrew hairs, poor wound healing, subperiosteal bleeding |
| Thiamine (B1) | Cofactor of pyruvate dehydrogenase and transketolase | Dry beriberi (neuropathy), wet beriberi (high-output heart failure), Wernicke-Korsakoff |
| Niacin (B3) | NAD and NADP | Pellagra: photosensitive dermatitis, diarrhoea, dementia |
| Folate and B12 | DNA synthesis | Megaloblastic anaemia; B12 also subacute combined degeneration; folate lack: neural tube defects |
| Vitamin K | Carboxylation of factors II, VII, IX, X, protein C and S | Bleeding; haemorrhagic disease of the newborn |
| Vitamin E | Membrane antioxidant | Haemolysis, spinocerebellar ataxia, neuropathy |
Test yourself
Think of the answer, then tap the question to see it.
Why do the gums bleed in scurvy?
Without vitamin C, collagen cannot be hydroxylated and cross-linked, so capillary walls and gums are fragile.
What is the difference between rickets and osteomalacia?
Both are defective mineralisation of osteoid from vitamin D lack; rickets occurs in growing children (growth plates involved), osteomalacia in adults.
Which deficiency causes squamous metaplasia of the respiratory epithelium?
Vitamin A deficiency.
Which finding separates B12 deficiency from folate deficiency?
B12 deficiency gives neurological damage (subacute combined degeneration) and high methylmalonic acid; folate deficiency does not.
Related
Related conditions
- Vitamin A deficiency (night blindness and xerophthalmia)
- Rickets and osteomalacia
- Scurvy (vitamin C deficiency)
- Beriberi (thiamine deficiency)
- Pellagra (niacin deficiency)
- Megaloblastic anaemia (B12 or folate deficiency)
- Wernicke encephalopathy (thiamine deficiency)
- Pernicious anaemia
- Subacute combined degeneration (vitamin B12)
- Vitamin K deficiency bleeding of the newborn
- Spina bifida (myelomeningocele)
- Hypervitaminosis A (vitamin A toxicity)
- Hartnup disease
Elsewhere in DurgiPedia
- Vitamin A (retinol)
- Vitamin D (calcitriol)
- Vitamin C (ascorbic acid)
- Thiamine (vitamin B1)
- Niacin (vitamin B3)
- Folate (vitamin B9)
- Cobalamin (vitamin B12)
- Vitamin K (phylloquinone)
- Vitamin E (α-tocopherol)
- Collagen synthesis
- Vitamins and minerals: a physiological overview
- Calcium regulation: PTH, vitamin D and calcitonin
- Folic acid and neural tube defect prevention
Educational content on the mechanisms of disease; not a diagnostic or treatment guide and no substitute for a health professional's advice. No doses are given.
Sources: Vitamin A deficiency (World Health Organization, 2026); Scurvy: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Beriberi: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026); Pellagra: MedlinePlus Medical Encyclopedia (MedlinePlus, US National Library of Medicine, 2026).
Spotted a mistake?We are always improving for the community. Tell us what is wrong and our team will review it.Report a mistake
Representative model, for educational purposes only.