Final exam review

Fat-soluble vitamins, essential for proper body function, are absorbed alongside lipids, forming micelles for transport.

Phylloquinone (K1) is a key form of vitamin K obtained from plant sources, like leafy greens.

Menaquinone (K2) is another form of Vitamin K produced by bacteria in the gut and found in animal sources, like meat and dairy.

Vitamin K plays a crucial role in blood clotting by activating proteins like prothrombin. This activation involves the addition of a carboxyl group (COOH) to specific amino acids, a process termed carboxylation.

A deficiency in Vitamin K can lead to increased bleeding and slower clotting times, potentially affecting the body's ability to repair injuries.

The most stable form of folate found in food, used in the body for various metabolic reactions. It is also found in supplements and fortified foods.

The form of folate primarily found in the blood stream. It is readily absorbed by the body.

Forms of folate found within cells where they are utilized for specific metabolic functions.

The process of breaking down and reusing folate in the body. This ensures an efficient use of available folate.

A condition caused by deficiency in folate and vitamin B12, characterized by abnormally large red blood cells, due to impaired DNA synthesis and cell division.

The amino acid involved in various metabolic processes and is a precursor to S-adenosylmethionine (SAM). Its synthesis requires folate.

A coenzyme derived from methionine, essential for various cellular processes like DNA methylation, neurotransmitter synthesis and immune function.

A crucial aspect of folate metabolism where folate is converted into various utilizable forms. Key tissues involved are RBCs and GI tract epithelial cells.

The process by which folate is absorbed into the body and transported in the bloodstream.

Folate is stored in various tissues throughout the body, notably in the liver, where it can be utilized later as needed.

A condition characterized by soft and brittle bones due to lack of bone mineralization, often accompanied by bone pain, particularly in elderly individuals and those with fat malabsorption.

A condition in which the bones become rubbery and legs bow due to insufficient bone mineralization, primarily affecting children.

A process involving cellular uptake and intracellular calcium flux, triggered by the presence of vitamin D.

A process where vitamin D receptors in the nucleus play a role in regulating gene expression.

A hormone secreted by the parathyroid glands in response to low blood calcium levels. PTH stimulates calcium mobilization from bone, increases calcium absorption in the intestines, and promotes calcium reabsorption in the kidneys.

The process of reducing polyglutamates to monoglutamates, a necessary step for the absorption of folate.

The process of storing vitamin D in the liver and adipose tissue.

The process of releasing stored vitamin D from the liver and adipose tissue, primarily when weight loss occurs.

The process of eliminating excess calcium from the body.

Tocopherols are found in plant sources, while tocotrienols are found in seeds, legumes, and oils.

Vitamin E acts as an antioxidant, protecting cell membranes and lipoproteins from damage caused by free radicals.

A condition characterized by muscle weakness due to vitamin E deficiency.

A rare neurological disorder caused by vitamin E deficiency, leading to problems with coordination and movement.

A synthetic form of folate found in supplements and fortified foods.

A deficiency in folate can lead to various health problems, including depression, dementia, peripheral neuropathy, and an increased risk of birth defects. It's relatively common in the US.

Vitamin B12 is a unique vitamin containing cobalt, primarily found in animal products and fermented foods.

Vitamin B12 absorption is low, typically around 50% for normal intake. However, as intake increases, the absorption efficiency decreases.

The body stores Vitamin B12 primarily in the liver, with smaller amounts found in muscles, bone, kidneys, heart, brain, and spleen.

Vitamin B12 is crucial for maintaining healthy nerve cells and red blood cells, and plays a role in DNA synthesis.

Vitamin B12 deficiency, often caused by inadequate absorption, can lead to neurological problems and anemia.

Vegetarians and vegans have a higher risk of vitamin B12 deficiency due to its limited presence in plant-derived foods.

Methylcobalamin and 5-deoxyadenosylcobalamin are the primary forms of vitamin B12 used by the human body.

Older individuals are more susceptible to low Vitamin B12 levels due to age-related factors that can affect absorption.

Cobalamin deficiency (SCCD) is the term for a lack of vitamin B12 in the body. It is far more common than clinical deficiency.

Haptocorrin (HC, R-binder, TCI) is a protein produced by white blood cells that carries approximately 80% of B12 in the blood. It has a half-life of about 10 days.

About 56% of vitamin B12 is absorbed when only 1 microgram is ingested. However, this absorption rate drops to just 16% with a 10 microgram intake.

Two essential enzymatic reactions require B12 in our bodies: 1. Cytoplasmic methionine synthase, 2. Mitochondrial methylmalonyl-CoA mutase.

A healthy adult has enough B12 stored to prevent deficiency for approximately 3 to 5 years with no further intake.

Heme iron, found in meats, fish, and poultry, accounts for 50-60% of the iron in our diet.

Nonheme iron is found in plant foods and is not as readily absorbed as heme iron.

Ferritin is the primary storage form of iron in the body, holding up to 4500 times the usual amount.

Iron (Fe) is essential for various bodily functions, including oxygen transport, cell growth, and energy production.

Factors like polyphenols (in tea or coffee), oxalates (in spinach), and low iron status can hinder iron absorption.

Ferroportin is a protein that transports iron across the intestinal cell membrane into the blood.

Hepcidin, a protein produced by the liver, regulates iron absorption and metabolism in the body.

Iron overload can be dangerous, leading to various health issues.

Iron deficiency can cause fatigue, shortness of breath, and other health problems.