Nutrients are chemical substances obtained from food that the body needs for growth, maintenance, and repair. Nurses must understand nutritional science because food directly influences healing, immune function, and recovery times in clinical wards. Malnutrition often prolongs hospital stays and increases complication rates among admitted patients. Assessing dietary intake forms a core part of holistic nursing care across primary health clinics and tertiary hospitals in Nigeria.
Macronutrients provide the bulk energy required for daily metabolic processes and physical activity. They are required in large gram quantities daily.
Micronutrients consist of vitamins and minerals needed in small milligram or microgram amounts to regulate chemical reactions in the body. Although they do not yield energy, life cannot be sustained without them.
| Micronutrient Type | Primary Role | Common Deficiency Sign | Local Dietary Source |
|---|---|---|---|
| Vitamin A | Vision and immunity | Night blindness | Palm oil, carrots |
| Iron | Oxygen transport in blood | Fatigue and pallor | Green leafy vegetables, liver |
| Calcium | Bone strength and clotting | Muscle tetany | Small fish with bones, milk |
| Vitamin C | Collagen synthesis and healing | Scurvy and bleeding gums | Oranges, tomatoes, guava |
Water is the most critical nutrient for human survival, making up over half of total body weight. It acts as a universal solvent, regulates body temperature through perspiration, and maintains blood volume. Nurses monitor intake and output charts carefully to prevent dehydration or fluid overload, especially in patients experiencing vomiting, diarrhea, or severe fevers.
Nutrients must be broken down mechanically and enzymatically before cells can use them. Digestion begins in the mouth with salivary amylase and continues through the stomach and small intestine. The small intestine, featuring villi and microvilli, absorbs simple sugars, amino acids, fatty acids, and micronutrients into the bloodstream or lymphatic system. Once absorbed, metabolic pathways convert these molecules into cellular energy or structural components.
Nutritional assessment involves anthropometric measurements like weight, height, and mid-upper arm circumference, alongside dietary histories and biochemical lab tests such as serum albumin. In Nigeria, food guidelines emphasize utilizing locally available staples like yam, cassava, beans, sorghum, and vegetables. Public health nurses promote culturally appropriate, balanced diets that combine cereals and legumes to achieve complete protein profiles.
Imbalances in nutrient intake lead to distinct pathological states. Deficiencies result in deficiency diseases like kwashiorkor from protein shortage, marasmus from overall calorie lack, or scurvy from vitamin C absence. Conversely, nutrient excesses, particularly of fats and refined carbohydrates, contribute heavily to non-communicable diseases such as obesity, type 2 diabetes, and hypertension.