Overview of Vitamins
Vitamins are organic compounds with carbon in their chemical structure that often act as coenzymes or enzyme precursors.
Examples:
- Energy metabolism: B vitamins (thiamine, riboflavin)
- DNA synthesis: Folate (B9), vitamin B12
- Immune function: Vitamin A
Classification:
- Fat-soluble: A, D, E, K (absorbed with fat, stored in tissues)
- Water-soluble: B-complex, C (not stored, excess excreted)
13 vitamins are considered essential nutrients
Water-Soluble Vitamins
| Water-Soluble Vitamin | Function | RDA (adult) | Food source |
| B1, Thiamine, | Energy metabolism, cardiac, nerves | 1.1 – 1.2 mg | Lean meat (pork), fish, legumes, nuts, fortified |
| B2, Riboflavin | Energy metabolism, mucus membranes | 1.1-1.3 mg | Lean meat, eggs, dairy, fortified grains/cereals |
| B3, Niacin | Energy metabolism | 14-16mg NE | Protein-rich foods, fortified grains/cereals |
| B5, Pantothenic acid | Energy metabolism | 5 mg | As above, whole grains, some vegetables |
| B6, Pyridoxine | Metabolism, immune, nerves, hgb*, blood glucose | 1.3-1.7 mg | Chickpeas, fish, meat, poultry, starchy vegetables |
| B7, Biotin | Energy metabolism, fatty acid & glycogen synthesis | 30 mcg | Protein-rich foods, sunflower seeds, sweet potato, almonds |
| B9, Folate | Cell formation, prevent birth defects | 400 mcg | Nuts, beans, protein-rich foods, leafy greens |
| B12, Cobalamin | Cells, metabolism, nerves | 2.4 mcg | Land animal protein, seafood |
| C, Ascorbic acid | Cells, immune, antioxidant, wound-healing, metabolism | 75-90 mg | Citrus fruit, tomato, potato, peppers, broccoli |
*hemoglobin
Fat-Soluble Vitamins
| Fat-Soluble Vitamin | Function | RDA (adults) | Food sources |
| A | Vision, immune, epithelial, bone | 700-900 mcg RAE | Eggs, fish, dairy, sweet potato, orange produce |
| D | Bone, Neuromuscular, immune | 600-800 IU | Cod liver oil, fatty fish, egg yolk, mushrooms |
| E | Antioxidant, cell integrity, immune | 15 mg | Nuts, seeds, avocado, broccoli, leafy greens |
| K | Blood coagulation, bone, cardiovascular, homeostasis | 90-120 mcg | Natto, leafy greens, broccoli, soybean and canola oil |
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