13 essential vitamins and their functions, how to get them through food

May 13, 2025

Vitamins are organic compounds your body needs in small amounts to function optimally. Unlike macronutrients, they don’t provide energy but act as catalysts for critical biochemical processes. Let’s decode these 13 micronutrients and their dietary sources through a science-backed lens.

 

I. Fat-Soluble Vitamins: Stored Allies

Require dietary fat for absorption; stored in liver/adipose tissue.

1. Vitamin A (Retinol), CAS No. 68-26-8

   • Roles: Night vision, immune defense, skin/cell regeneration.
   • Key Sources:
     🥕 Carrots (beta-carotene) | 🥚 Egg yolks | 🧀 Cheddar cheese
     Pro Tip: Pair with olive oil for 6x better absorption of plant-based carotenoids.

2. Vitamin D (Sunshine Vitamin), CAS No. 1406-16-2

   • Roles: Calcium absorption, bone remodeling, immune modulation.
   • Key Sources:
     ☀️ 15-min midday sun exposure | 🐟 Wild salmon | 🥛 Fortified plant milk
     Fact: 50% of adults globally are deficient due to indoor lifestyles.

3. Vitamin E (Tocopherol), CAS No. 1406-18-4

   • Roles: Antioxidant shield, protects cell membranes, anti-inflammatory.
   • Key Sources:
     🌰 Almonds | 🌻 Sunflower seeds | 🥑 Avocado
     Bonus: 30g almonds = 100% daily needs.

4. Vitamin K (Phylloquinone), CAS No. 12001-79-5

   • Roles: Blood clotting, bone mineralization, arterial health.
   • Key Sources:
     🥬 Kale | 🥦 Broccoli | 🧀 Fermented natto
     Science Insight: K₂ reverses arterial calcification in early stages.

 

II. Water-Soluble Vitamins: Daily Essentials

Require regular intake; excess excreted in urine (except B12).

The B-Complex Brigade

Vitamin	Primary Mission	Top Food Sources	Deficiency Risks
B₁ (Thiamine)	Converts carbs to energy	🌾 Oats, 🐖 Pork loin	Beriberi, nerve damage
B₂ (Riboflavin)	Energy metabolism, skin health	🥛 Yogurt, 🥚 Eggs	Cracked lips, sore throat
B₃ (Niacin)	DNA repair, cholesterol balance	🐔 Chicken, 🥜 Peanuts	Pellagra (dermatitis)
B₅ (Pantothenic Acid)	Hormone synthesis	🥑 Avocado, 🍄 Shiitake	Fatigue, insomnia
B₆ (Pyridoxine)	Neurotransmitter production	🍌 Banana, 🥔 Potato	Anemia, weakened immunity
B₇ (Biotin)	Hair/nail strength, gene expression	🌰 Walnuts, 🥚 Whole eggs	Hair loss, scaly rash
B₉ (Folate)	DNA synthesis, fetal development	🥬 Spinach, 🍊 Orange	Neural tube defects
B₁₂ (Cobalamin)	Nerve myelination, red blood cells	🦪 Oysters, 🥩 Beef liver	Pernicious anemia

 

Vitamin C (Ascorbic Acid), CAS No. 50-81-7

• Roles: Collagen synthesis, antioxidant defense, iron absorption.
• Key Sources:
  🍓 Strawberries | 🫑 Red bell pepper | 🥝 Kiwi
  Storage Hack: Eat raw—cooking destroys 50% of vitamin C!

 

III. Smart Intake Strategies

1. Synergy Combos:

   • Iron + C: Lentils 🫘 + lemon juice 🍋 (enhances iron absorption).
   • D + Calcium: Sardines 🐟 + bok choy 🥬 (bone-building duo).
   • E + Selenium: Brazil nuts 🌰 + sunflower seeds 🌻 (amplified antioxidant effect).

2. Rainbow Diet: Consume 5 colors daily for vitamin diversity:
   🔴 Tomato (lycopene) | 🟠 Sweet potato (beta-carotene) | 🟢 Kale (folate) | 🔵 Blueberries (C) | ⚪ Garlic (B₆).

3. At-Risk Groups:

   • Vegans: Supplement B₁₂; try nutritional yeast.
   • Pregnant Women: 600 mcg folate + prenatal D.
   • Seniors: Monitor B₁₂/D levels; consider fortified foods.

 

Final Thought: While supplements have their place, whole foods provide vitamins in bioactive forms with complementary phytonutrients. Your plate is the ultimate multivitamin—design it wisely!