Vitamin and Mineral Deficiency Table
| Nutrient | Function | Deficiency disease | Symptoms | Sources |
|---|---|---|---|---|
| Vitamin C | Needed for making connective tissue (collagen); maintaining healthy skin, gums and blood vessels | Scurvy | Bleeding gums, loose teeth, slow wound healing, fatigue, joint pain | Citrus fruits, peppers, broccoli, strawberries, tomatoes |
| Vitamin D | Needed for absorption of calcium from the gut; bone mineralisation | Rickets (children) / Osteomalacia (adults) | Soft, weak bones that bend under body weight; bowed legs in children | Oily fish, eggs, dairy; also made by skin when exposed to sunlight |
| Iron | Component of haemoglobin in red blood cells | Iron-deficiency anaemia | Tiredness, weakness, pale skin, shortness of breath (fewer red blood cells → less oxygen carried) | Red meat, liver, spinach, lentils, fortified cereals |
| Calcium | Needed for strong bones and teeth; muscle contraction; blood clotting | Weak bones and teeth; increased risk of fractures | Brittle bones, poor dental health, muscle cramps | Dairy products, green leafy vegetables, fortified plant milks, small fish with bones |
Linking Vitamin D and Calcium
Vitamin D and calcium work together for bone health:
- Vitamin D is needed for the absorption of calcium from the small intestine.
- Even if a person eats enough calcium, a vitamin D deficiency means the calcium cannot be properly absorbed.
- Both deficiencies lead to weak bones, but through different mechanisms.
Vitamin D is unique: it can be made by the body. When UV light from the sun hits the skin, a chemical reaction produces vitamin D. This is why people who get very little sunlight (e.g. In northern climates, or who cover most of their skin) are at higher risk of vitamin D deficiency.
Iron-Deficiency Anaemia in Detail
Iron is a component of haemoglobin, the protein in red blood cells that carries oxygen.
Without enough iron:
- The body cannot produce enough haemoglobin.
- Red blood cells contain less haemoglobin → they carry less oxygen.
- Cells receive less oxygen → less aerobic respiration → less energy released.
- Symptoms: persistent tiredness, weakness, pale skin, breathlessness during exercise.
Groups at higher risk: women (menstruation causes iron loss), pregnant women (iron needed for baby's blood), vegans (plant-based iron is less easily absorbed than animal-based iron).