Overfed and undernourished: what is malnutrition and nutrient deficiency?
More than 800,000 patients were admitted to hospital with malnutrition and nutritional deficiencies last year, according to NHS figures.
Hospital data for England and Wales, obtained by the Guardian, reveals a threefold increase in diagnoses linked to poor diet in the past decade, with nearly half a million people admitted to hospital with iron deficiencies, hundreds of thousands with vitamin deficiencies and more than 10,000 cases of malnutrition last year.
Malnutrition
To stay healthy, the body needs a minimum daily intake of food and water and also the right balance of nutrients. A healthy diet should not simply stave off hunger but needs to include carbohydrates, protein, fat, fibre, vitamins, minerals and water. Not getting enough calories leads to weight loss, muscle and bone weakness, fatigue and, in children, affects growth. However, it is possible to eat a high-calorie diet that is lacking essential nutrients, meaning that obesity and protein, vitamin or mineral deficiencies can occur. Malnutrition also stresses and diminishes immune function, making the body less able to keep infectious diseases at bay.
Iron deficiency
Good sources of iron include red meat, eggs, kidney beans, nuts and fortified breakfast cereals. Iron is essential for haemoglobin, the protein in red blood cells that carries oxygen from the lungs to the rest of the body. Without enough iron, the body makes fewer red blood cells or cells that are not as good at transporting oxygen. Symptoms include a pallid complexion, unexplained fatigue or dizziness, headaches and heart palpitations. Untreated iron deficiency can increase the risk of illnesses and infections because a lack of iron affects the immune system. Heavy periods and pregnancy can cause iron deficiency, meaning that teenage girls and women are generally at greater risk.
Vitamin B deficiency
B vitamins come in a variety of forms, including thiamin, niacin, B6, B12 and folate and folic acid. B vitamins are found in grains and cereals; B12 is found in dairy products and folate in leafy vegetables. B vitamins play a crucial role in maintaining the health of the central (brain and spine) and peripheral nervous systems. Deficiencies can lead to tingling and neurological symptoms, including altered vision, impaired cognition and confusion. In children, B vitamins are important for healthy brain development. Older people are at particular risk of B12 deficiencies because it is absorbed by stomach acid, which declines with age. If deficiencies are not reversed quickly, irreversible nerve damage can occur.
Vitamin D deficiency
Vitamin D is produced in the skin during exposure to direct sunlight and, for most people, this provides enough of the vitamin between April and September. However, in winter months, dietary sources, such as oily fish, meat and eggs, or supplements are needed to top up vitamin D levels. In the UK, children up to their fifth birthday are advised to take a multivitamin containing vitamins A, C and D and those on low incomes are entitled to free vitamins. The NHS also advises adults to consider taking supplements during the winter. Low levels of vitamin D have been linked with low mood and depression. It also helps the body absorb calcium and therefore contributes to bone health. Vitamin D or calcium deficiency are the most common causes of rickets, a condition that causes the bones to soften and deform.