Yuva Skin & Aesthetics

Water-soluble vitamins perform a wide range of important functions, including the extraction of energy from food, cell signalling, synthesis of DNA and conduction  of nerve impulses. Water-soluble vitamins comprise nine compounds – vitamins B1, B2, B6, B12, C, niacin, folate, biotin and pantothenic acid – distinguished by their chemistry and function. They are required regularly in small amounts in the human diet as they are not stored in the body; excess intake is removed by the kidneys. Symptoms of deficiency may occur if a diet lacks any one of these vitamins.  For example, a diet lacking in vitamin C can lead to the development of scurvy, characterized by impaired wound healing, joint pain, tiredness and shortness of breath; a diet lacking in vitamin B12 may lead to anaemia and degeneration of the spinal cord. It has proved difficult to know exactly how much of each vitamin is required daily to stay healthy. Early experiments (that would be considered unethical...

Vitamins A, D, E and K comprise a small group of fat-soluble vitamins of disparate chemical composition which are essential for good health.  Various processes are dependent on an adequate availability of these vitamins, including vision (vitamin A), growth and tissue differentiation (vitamins A and D), bone and muscle function (vitamin D), immune function (vitamin A), protection against  free radicals (vitamin E) and blood clotting (vitamin  K). Although fat-soluble vitamins can  be stored in the body for use in times of dietary scarcity, deficiencies do occur, with profound consequences.  In some regions of the world, young children are at risk of becoming blind because of inadequate vitamin A. Vitamin D deficiency, which is common worldwide, may cause bowed legs and pelvic deformities of rickets in children and muscle weakness and bone pain of osteomalacia in adults.  Foods  of animal origin tend to be good sources of fat-soluble vitamin...

Minerals are inorganic substances that are not made by living things. Found  in both soil and rocks, they are absorbed by plants that are then eaten.  Minerals are  largely classified as ‘major’ minerals or ‘trace’ minerals. Major minerals are those that the  body requires in amounts of at least 100 mg per day, and include sodium, potassium, calcium, magnesium, sulphur, phosphorus and chloride. Trace minerals are needed in amounts of less than 100 mg per day, and some, such as iron, fluoride, zinc and manganese, have established recommended daily allowances (RDAs) or Adequate Intake (AI) limits to ensure adequacy.  A third classification, known as ‘ultra-trace’ minerals, require less than 1 mg per day, and include chromium, copper, iodine, molybdenum and selenium.  Minerals play a role in maintaining a healthy immune system, bone and teeth health, muscle contraction, fluid balance  and overall growth. A healthy diet of fruits, vegetables, w...

Fat is familiar to us as a substance we eat in food and store in our body. Both  have the same chemical structure known  as triaclyglycerol (TAG), which, when overconsumed in food, accumulates as body fat  and increases body weight.  The average 70-kg (155-lb) man has about 15 kg (33 lb) of body  fat, which is equivalent to 140,000 calories or 40 days of stored energy, but only 0.3 kg (10 oz) of stored carbohydrate (900 calories).  The physical and chemical properties of fats (TAG)  in food are determined by differences in their component fatty acids (FAs), which differ in size and number of carbon double bonds. Saturated fats are mainly derived from animal sources  and are solid at room temperature due to  a lack of double bonds (such as butter),  while monounsaturated fats have one, and polyunsaturated fats have two or more double bonds, which turn these fats into liquid oils.  These oils can be extracted from plant se...

Dietary fibre is the indigestible component of foods and drinks which has a bulking effect in the large intestine and provides a substrate for the colonic bacteria.  Originally, ‘fibre’ was limited to non-starch polysaccharides (such as cellulose) plus lignin from plants. In recent years the definition of fibre has widened to include all food components that are not digested and absorbed in the small intestine, including the non-digestible oligosaccharides (which are between the simple sugars and the starch polymers) and resistant starch.  There  is also an increasing use of novel, synthetic f ibres in processed foods and drinks. Recent research suggests that a high intake of dietary fibre, particularly cereal fibre and whole  grains, is associated with a reduced risk of cardiometabolic disease and colorectal cancer.     Higher intakes of some fibre components are also associated with reductions in serum cholesterol and triacylglycerols as ...

Carbohydrates are one of the main components of the diet (the macronutrients) and provide the major substrate for energy metabolism within the brain, kidney medulla and red blood cells.        Carbohydrates are also important for muscle function in highintensity exercise. Whilst dietary carbohydrates can range from molecules such as glucose and fructose (the simple sugars), through the disaccharides (sucrose, maltose, lactose) to the complex polymers of glucose found in starch, all dietary forms are digested within the intestine so that the simple sugars are the molecules  that are absorbed into the body.       Dietary recommendations for healthy people suggest carbohydrates should provide between 45 and 60% of dietary energy, depending on age, physical activity and body weight.       High intakes of the simple sugars, sucrose or maltose, and even rapidly digested refined grains, are associated with risks to health,...