Understanding Starches: Key to Sustained Energy and Nutritional Balance

Starches, a type of carbohydrate, are foundational to a balanced diet, providing sustained energy and essential nutrients. As complex carbohydrates, starches consist of long chains of glucose molecules, which require a gradual breakdown in the digestive system. Enzymes in the mouth and intestines convert these chains into simpler sugars, primarily glucose, which then enters the bloodstream to fuel bodily functions. This process allows for a steady release of energy, unlike simple sugars that lead to quick spikes and crashes. This sustained energy release from starches is ideal for supporting physical activity and mental focus throughout the day.

Starches are found in a range of whole foods, with primary sources being grains (like rice, wheat, and corn), root vegetables (such as potatoes, sweet potatoes, and yams), and legumes (like beans and lentils). Each source provides distinct nutritional benefits. Whole grains, for instance, are rich in fiber, which aids digestion and regulates blood sugar by slowing glucose absorption. Fiber also promotes satiety, helping with weight management and reducing cravings for unhealthy snacks. Additionally, whole grains and starchy vegetables deliver important vitamins and minerals, including B vitamins for energy production, iron for oxygen transport, and magnesium for muscle and nerve function.

However, not all starches are equally beneficial. Refined starches, like those in white bread, pastries, and processed snacks, lack fiber and other nutrients stripped away during processing. These refined starches cause rapid spikes in blood sugar, potentially leading to insulin resistance, weight gain, and an increased risk of chronic diseases such as diabetes and heart disease. The rise of ultra-processed foods, high in refined starches, has been linked to higher rates of obesity and metabolic disorders globally.

For optimal health, nutritionists recommend prioritizing whole, minimally processed sources of starch, such as quinoa, oats, and legumes, and reducing intake of refined starches. Incorporating a variety of whole grains, legumes, and starchy vegetables supports long-term health by balancing energy levels, promoting digestive health, and supplying essential nutrients for overall well-being.
Understanding Starches: Key to Sustained Energy and Nutritional Balance

Food sources and functions of potassium

Potassium is found naturally in many foods and as a supplement. Bananas are often touted as a good source of potassium, but other fruits (such as apricots, prunes, and orange juice) and vegetables (such as squash and potatoes) also contain this often-neglected nutrient.

Other sources of potassium in the diet include leafy greens, such as spinach and collards. Bran cereal, nuts, molasses, meat, poultry, brown rice, whole-wheat bread and whole-wheat pasta are also a good source of potassium.

Potassium’s main role in the body is to help maintain normal levels of fluid inside our cells. Sodium, its counterpart, maintains normal fluid levels outside of cells. Potassium is a dietary mineral that is also known as an electrolyte, essential to both cellular and electrical function.

Intracellular fluid contains about 95 percent of the body’s potassium, with the highest amount in skeletal muscle cells.

Potassium also helps muscles to contract and supports normal blood pressure. The flow of sodium and potassium in and out of cells is an important component of muscle contractions and the transmission of nerve impulses. The central nervous system (CNS) zealously protects it potassium – CNS potassium levels remain constant even in the face of falling levels in the muscle and blood.

Potassium helps move nutrients into cells and waste products out of cells. A diet rich in potassium helps to offset some of sodium's harmful effects on blood pressure. There is also suggestion that increasing potassium intake may be key in lowering blood pressure and reducing the risk of stroke, congestive heart failure and cardiac arrhythmias.

A low potassium level can make muscles feel weak, cramp, twitch, or even become paralyzed, and abnormal heart rhythms may develop.
Food sources and functions of potassium

Food sources of Vitamin D

Vitamin D is a fat-soluble vitamin that has long been known to help the body absorb and retain calcium and phosphorus; both are critical for building bone.

Few foods naturally contain vitamin D, though some foods are fortified with the vitamin. Fortified forms are included in milk, cereals, and some margarines. The chief food sources of vitamin D in western diets are fortified milk and cereals, and fatty fish. Cereals are considered the best breakfast supported with essential vitamins and nutrients, including vitamin D, in reasonable amounts. For most people, the best way to get enough vitamin D is taking a supplement because it is hard to eat enough through food.

Since milk, human as well as cow’s, is not a good source of vitamin D, a small supplement is required for both breast-fed and bottle-fed infants. Fish liver oil preparations are normally used as supplements for the supply of vitamins A and D.

Natural sources include fish oils, salmon, sardines, herring, liver, and egg yolks. Egg yolk contains 18 IU of vitamin D. Cheese is among the best foods high in Vitamin D. It is valued for its high content of phosphorus, fat, protein, vitamins, and calcium.

Two basic substances with vitamin D activity, D2 and D3, occur only in yeast and fish liver oils. A fish can naturally store vitamin D in its liver and fat tissues. Sardines, mackerel, trout are some fish that are food with vitamin D.

Salmon is a popular fatty fish and a great source of vitamin D. According to the United States Department of Agriculture (USDA) Food Composition Database, one 3.5-ounce (100-gram) serving of farmed Atlantic salmon contains 526 IU of vitamin D, or 66% of the DV

Mushroom also contain a small amount of vitamin D. This include mushroom shiitake and maitake mushroom – when they are dried outdoors such as under the summer sun for six and eight hours.

The daily value (DV) for vitamin D is 800 IU (20 mcg). The vitamin D content is listed as a percentage of the DV on the nutrition facts label on food packages.
Food sources of Vitamin D

Function, deficiency and food sources of calcium

Physical Function
Structural component of bones and teeth; role in intracellular and hormonal secretion regulation, muscle contraction, and activation of some enzyme systems.

Calcium is maintained relatively high concentration in the blood and extracellular fluids, where it is needed to facilitate such functions as blood coagulation and intercellular communications. Blood calcium levels are rigorously controlled so that if blood levels drop the body will rapidly respond by stimulating bone resorption, thereby releasing stored calcium into the blood.

Calcium also enables human blood to clot normally and regulates our muscle contractions, including heartbeat

The most well-known calcium function is to build and strengthen bones and teeth. The calcium in bones serves as a reservoir for calcium that is needed throughout the body. Calcium helps human bones to grow strong until the age of 20-25, when bone density reaches its peak. About 99% of the body’s calcium is stored in bones, and the remaining 1% is found in blood, muscle, and other tissues.

Calcium also is the key factor in normal transmission of nerve impulses. Calcium binds to vesicles that contain neurotransmitters, causing a release into the neural synapses (junction between nerve cells). This allows the flow of ions in and out of nerve cells. If calcium is lacking, nerve-cell function will fail.

Calcium is a key component of the cell membrane and controls cell permeability and electrical properties.

In order to perform daily functions, the body works to keep a steady amount of calcium in the blood and tissues. If calcium levels drop too low in the blood, parathyroid hormone (PTH) will signal the bones to release calcium into the bloodstream.

Deficiency symptoms
A low calcium intake during the growing years limits the bones’ ability to reach their optimal mass and density.

The symptoms of calcium deficiency include rickets, osteomalacia, osteoporosis, scurvy, tetany, parathyroid hyperplasia, stunted growth, laryngospasm.

Deficiency of calcium in young girls causes late puberty, irregular menstruation, excessive bleeding with crampy pain during this period, anemia and lowered state of body resistance against infection.

A more serious deficiency of calcium, called hypocalcemia, results from diseases such as kidney failure, surgeries of the digestive tract like gastric bypass, or medications like diuretics that interfere with absorption.

Food sources
Calcium is found in milk, milk products, sardines, clams, oysters, cheese and dairy foods, dark green vegetables (turnip greens, broccoli, legumes), dried fruits and nuts.

Calcium is classically associated with dairy products: milk, yoghurt and cheeses are rich sources of calcium, providing the major share of calcium from foods in the general diet in the United States and Canada.

When substantial amounts of grains are consumed, for like breads or as maize, these can be important sources, although the calcium in cereals tends to be less bioavailable than that in dairy products.
Function, deficiency and food sources of calcium

Food sources of vitamin E

Vitamin E was discovered in 1922 but it was not until 40 years later that the vitamin was established as essential to human nutrition. Vitamin E is a fat-soluble vitamin and its main function is as an antioxidant, helping to protect cells from the damage caused by free radicals. People are also exposed to free radicals in the environment from cigarette smoke, air pollution, and ultraviolet light from the sun.

Since vitamin E is synthesized only in plants, the vitamin is an essential nutrient in the diet of animals and man.

Vitamin E is present in human tissues and it is necessary for normal metabolism. It is found to be widely distributed in foods.

Vitamin E is synthesized only by plants and, therefore, is found primarily in plant products, the richest sources being vegetable oils and products made from them, such as margarine and salad dressings.

Among vegetable oils, the content of vitamin E isomers differs vastly. Some vegetable oils such as olive, safflower and sunflower are rich in alpha-tocopherol, while other oils such as sesame seed, and rapeseed oil are rich in gamma-tocopherol. Corn and soybean oils also rich in gamma-tocopherol.

The dietary sources of tocotrienols are palm oil, rice bran oil, and the bran and germ portions of cereals such as oat, barley and rice.

Wheat germ oil is especially rich in vitamin E. While major sources of vitamin E in Japan are fish and shellfish.

Nuts (such as peanuts, hazelnuts, and, especially, almonds) and seeds (like sunflower seeds) are also among the best sources of vitamin E. Avocadoes are another good sources of vitamin E.
Food sources of vitamin E

Food sources of vitamin K

Vitamin K is a nutrient that the body needs to stay healthy. It’s important for blood clotting and healthy bones and also has other functions in the body.

Eating a variety of foods that contain vitamin K is the best way to get the amount human need. Cabbage, spinach, cauliflower, and liver are good source of vitamin K, although moderate amounts are found in many other vegetables, as well as in cereals. Vitamin K is found in multivitamin/multimineral supplements. Vitamin K is also available in supplements of vitamin K alone or of vitamin K with a few other nutrients such as calcium, magnesium, and/or vitamin D.

There are two forms of vitamin K: vitamin K1 and vitamin K2.
*Vitamin K1 is mostly found in plants and is human main dietary source of vitamin K.
*Vitamin K2 is found in fermented foods and in some meats and cheeses. It is also made by human body from the vitamin K1 in the food they eat.
Food sources of vitamin K

Folic acid in human body

The term ‘folic acid’ refers specifically to pteroylmonoglutamic acid which reference to the pteroic acid and glutamate moieties.

Folic acid is required for the formation of blood cells by the bone marrow and is involved in the formation of the blood pigment hemoglobin.

During pregnancy folic acid helps create red blood cells for the increased blood volume required by the mother, fetus and placenta.

asparagus

It is also required for the synthesis of some amino acids. Deficiency symptoms involve pernicious anemia.

Scientific experiments have revealed that folic acid deficiencies cause DNA damage resembling the DNA damage in cancer cells.

Folic acid is found in liver, dried beans, peas, lentils, orange, whole-wheat products, asparagus, beets, broccoli, Brussels sprouts and spinach.
Folic acid in human body 

Vitamin D from natural sources

Very few naturally occurring foods are rich in vitamin D. Typically animal foods contain cholecalciferol, while plant foods contain ergocalciferol. Some food items that naturally contain small amounts of vitamin D include oil fish such as salmon, mackerel and blue fish. Cod liver oil is the best source of vitamin D.

Liver meat is another source of abundant vitamin D. For vegetarians or vegans, all edible mushrooms have some content of vitamin D2 and ergosterol, which becomes activated with UVB exposure.

The two basic substances with vitamin D activity D2 and D3, occur only in yeast and fish liver oils. Vitamin D is also presents in small quantities in vegetables, meat and egg yolk.

The main food sources are those to which crystalline vitamin D has been added. Milk, because it is commonly used, has proved to be the most practical carrier. In United States fluid milk is voluntary fortified with 400 IU per quart of vitamin D.

The most efficient source of the vitamin D is not a food at all, but exposure to sunlight, which transforms a related pro-vitamin substance in the skin into a substance which the kidney can change into active vitamin D.

Sunlight provides 90 to 100% of the requirement for most people who are exposed to adequate sunlight. Vitamin D3 is synthesized in human skin from 7-dehydrocholesterol following exposure to ultraviolet B radiation with wavelength 290 to 320 nm.

Like other fat soluble vitamins, the sunlight activated pro-vitamin D can be stored away in the liver.
Vitamin D from natural sources

Vitamin A: functions and food sources

Vitamin plays a central role in many essential biological processes. Vitamin A (retinol) functions in reproduction, growth, the maintenance of skin and mucous membranes and the visual process.

Vitamin A is needed to process incoming light to visual images and to keep the eye’s surface healthy. Vitamin is known to be involved in fetal development and in the regulation of proliferation and differentiation of many types of cells throughout life. It plays a role in immune function, both as a cell regulator and by helping maintain the skin and mucous membranes.

Vitamin A is normally transported in the blood linked to a specific protein, retinol binding protein (RBP). Specific proteins on cell surfaces and within cells are also involved with intracellular transport of the vitamin.

Vitamin A is fat soluble and is primarily stored in the liver, where RBP is synthesized. The liver holds over 90 percent of the body’s vitamin A reserves, with the rest deposited in fat tissue, lungs and kidneys.

In a well nourished person, vitamin A stores are generally sufficient to last many months on a vitamins A-deficient diet before signs of deficiency appear.

The initial symptoms of vitamin A deficiency are night blindness and keratinization of hair follicles. Continued deficiency leads to damage to eye tissue and irreversible blindness.

The US recommended Daily Allowance (RDA) of vitamin A for adults is 5000 IU (1000 retinol equivalents). Main dietary sources of vitamin A are the carotenoids from fruits and vegetables. These carotenoids do seen to have a separate function as antioxidants in addition to their pro-vitamins A function.

Rich dietary sources of retinol (preformed vitamin A) include dairy products, eggs and organ meats. Some carotenoids (found in deep-yellow and dark green vegetables) can be converted to vitamin A during digestion. In the US diet, approximately half of the vitamin A activity is derived from B-carotene and other carotenoids.
Vitamin A: functions and food sources