Vitamin and Mineral Requirements in Human Nutrition

Vitamins and minerals are essential micronutrients that the body needs in small amounts to carry out a wide range of biochemical processes. While macronutrients (carbohydrates, proteins, and fats) provide energy, micronutrients act as cofactors, structural components, and regulators of metabolism. Adequate intake of each vitamin and mineral supports growth, immune function, bone health, and disease prevention. This page summarises the primary requirements for adults, highlights food sources, and notes considerations for specific population groups.

Vitamins

FatSoluble Vitamins

Fatsoluble vitamins are absorbed with dietary fat and stored in liver and adipose tissue. Because they can accumulate, both deficiency and toxicity are possible.

• Vitamin A (Retinol, carotene) 900g RAE (men) / 700g RAE (women)
  Key foods: liver, fortified dairy, carrots, sweet potatoes, dark leafy greens.
  Functions: vision, immune response, epithelial integrity.
• Vitamin D (Calciferol) 15g (600IU) for adults up to age 70; 20g (800IU) thereafter.
  Key foods: fatty fish, fortified milk, egg yolk; also synthesized by skin exposure to UVB.
  Functions: calcium absorption, bone mineralisation, modulation of immune function.
• Vitamin E (Tocopherol) 15mg tocopherol.
  Key foods: nuts, seeds, vegetable oils, green leafy vegetables.
  Functions: antioxidant protection of cell membranes, immune support.
• Vitamin K (Phylloquinone & Menaquinone) 120g (men) / 90g (women).
  Key foods: green leafy vegetables, cruciferous vegetables, fermented foods.
  Functions: synthesis of clotting factors, bone metabolism.

WaterSoluble Vitamins

These vitamins dissolve in water, are not stored in large amounts, and excess is usually excreted in urine.

• Vitamin C (Ascorbic acid) 90mg (men) / 75mg (women); smokers need an additional 35mg.
  Key foods: citrus fruits, strawberries, bell peppers, broccoli.
  Functions: collagen synthesis, antioxidant, enhances nonheme iron absorption.
• Thiamin (B1) 1.2mg (men) / 1.1mg (women).
  Key foods: whole grains, pork, legumes, nuts.
  Functions: carbohydrate metabolism, nerve function.
• Riboflavin (B2) 1.3mg (men) / 1.1mg (women).
  Key foods: dairy, eggs, lean meats, green vegetables.
  Functions: energy production, antioxidant regeneration.
• Niacin (B3) 16mg (men) / 14mg (women).
  Key foods: poultry, fish, whole grains, legumes.
  Functions: DNA repair, cholesterol metabolism.
• Vitamin B6 (Pyridoxine) 1.31.7mg (men) / 1.31.5mg (women, agedependent).
  Key foods: fish, beef liver, potatoes, noncitrus fruit.
  Functions: aminoacid metabolism, neurotransmitter synthesis.
• Folate (Vitamin B9) 400g DFE.
  Key foods: leafy greens, legumes, fortified cereals.
  Functions: DNA synthesis, cell division; critical during pregnancy to prevent neuraltube defects.
• Vitamin B12 (Cobalamin) 2.4g.
  Key foods: animal products (meat, dairy, eggs); fortified plant milks for vegans.
  Functions: redbloodcell formation, neurological health.
• Biotin 30g.
  Key foods: eggs, nuts, soybeans.
  Functions: fattyacid synthesis, gluconeogenesis.
• Pantothenic Acid 5mg.
  Key foods: chicken, beef, potatoes, oats.
  Functions: coenzyme A synthesis, energy metabolism.

Minerals

Macrominerals

• Calcium 1,000mg (adults 1950); 1,200mg (women >50 & men >70).
  Key foods: dairy, fortified plant milks, sardines with bone, leafy greens.
  Functions: bone & teeth formation, muscle contraction, nerve transmission.
• Phosphorus 700mg.
  Key foods: meat, dairy, nuts, legumes.
  Functions: bone matrix, ATP production, cellmembrane integrity.
• Magnesium 420mg (men) / 320mg (women).
  Key foods: nuts, seeds, whole grains, leafy greens.
  Functions: over 300 enzymatic reactions, muscle function, bloodpressure regulation.
• Sodium 1,500mg minimum; 2,300mg recommended limit.
  Key sources: salt, processed foods.
  Functions: fluid balance, nerve impulse transmission.
• Potassium 3,400mg (men) / 2,600mg (women).
  Key foods: bananas, potatoes, beans, yogurt.
  Functions: cellular electrolyte balance, bloodpressure control.
• Chloride 2,300mg.
  Key sources: table salt, many vegetables.
  Functions: gastric acid production, fluid balance.
• Sulfur not assigned an RDA; required in the form of sulfurcontaining amino acids.
  Key foods: proteinrich foods such as meat, legumes, nuts.

Trace Minerals

• Iron 8mg (men) / 18mg (women of reproductive age); 8mg postmenopause.
  Key foods: red meat, poultry, beans, fortified cereals, spinach (nonheme iron).
  Functions: hemoglobin formation, oxygen transport, energy metabolism.
• Zinc 11mg (men) / 8mg (women).
  Key foods: meat, shellfish, legumes, nuts, whole grains.
  Functions: immune function, wound healing, DNA synthesis.
• Copper 900g.
  Key foods: liver, shellfish, nuts, seeds, whole grains.
  Functions: iron metabolism, antioxidant enzyme (SOD) activity.
• Manganese 2.3mg (men) / 1.8mg (women).
  Key foods: nuts, whole grains, tea, leafy vegetables.
  Functions: bone formation, metabolism of carbohydrates and fats.
• Selenium 55g.
  Key foods: Brazil nuts, seafood, meat, cereals.
  Functions: antioxidant (glutathione peroxidase), thyroid hormone metabolism.
• Iodine 150g.
  Key foods: iodised salt, seaweed, dairy, fish.
  Functions: synthesis of thyroid hormones (T3, T4) regulating metabolism.
• Fluoride 4mg (men) / 3mg (women).
  Key sources: fluoridated water, tea, some fish.
  Functions: dental enamel mineralisation, bone strength.
• Chromium 35g (men) / 25g (women).
  Key foods: whole grains, meat, broccoli.
  Functions: potentiates insulin action, carbohydrate metabolism.
• Molybdenum 45g.
  Key foods: legumes, grains, nuts.
  Functions: cofactor for enzymes involved in sulfuraminoacid metabolism.

Factors Influencing Requirements

LifeStage and Gender

Pregnancy, lactation, childhood, and old age each modify needs. For example, pregnant women require an additional 300g of folate and 1mg of iron per day. Adolescents experience higher calcium and iron demands due to rapid growth.

Dietary Patterns

Vegetarians and vegans must pay special attention to vitamin B12, iron (nonheme), zinc, calcium, and omega3 fatty acids. Fortified foods or supplements often fill these gaps.

Health Status

Gastrointestinal disorders (celiac disease, Crohns disease) can impair absorption of fatsoluble vitamins and minerals such as calcium and iron. Chronic kidney disease affects phosphorus and potassium handling.

Medication Interactions

Some drugs interfere with micronutrient status: protonpump inhibitors reduce vitamin B12 absorption, diuretics increase urinary loss of calcium and magnesium, and oral contraceptives may elevate zinc requirements.

Meeting the Requirements

Achieving adequate micronutrient intake is best accomplished through a varied, balanced diet that includes:

• At least five servings of fruits and vegetables each day.
• Whole grains rather than refined cereals.
• A source of lean protein (meat, fish, poultry, legumes, or dairy) at most meals.
• Dairy or fortified alternatives for calcium and vitamin D.
• Regular consumption of nuts, seeds, and healthy oils for vitamin E and trace minerals.

When dietary intake is insufficient or a specific deficiency is diagnosed, targeted supplementation is appropriate. However, unnecessary highdose supplements can cause toxicity, particularly with fatsoluble vitamins (A, D, E, K) and certain minerals (iron, selenium).

Key Takeaways

• Vitamins and minerals are required in small amounts but have outsized effects on health.
• Recommended intakes differ by age, sex, and physiological state; reference values such as the Dietary Reference Intakes (DRIs) provide guidance.
• Whole foods supplies a synergistic matrix of micronutrients that is difficult to replicate with supplements alone.
• Special populations (pregnant women, older adults, vegans, people with chronic disease) should assess their intake more closely.
• Balance is essential: both deficiency and excess can lead to disease.

References: Institute of Medicine (US) Food and Nutrition Board. Dietary Reference Intakes. 2020. WHO. Micronutrient Guidelines. 2022.