Micronutrients in Metabolism
Is choline a vitamin? Why or why not?
Choline is a vitamin-like substance (it is a mineral) that is required for the production of phosphatidylcholine, a compound found in bile, and for the synthesis and release of the neurotransmitter acetycholine.
niacin
Niacin is a generic name for two specific vitamin compounds, nicotinic acid and nicotinamide,
Why is the RDA for niacin measured in niacin equivalents (NE)?
Niacin is a unique vitamin in that the body can synthesize a limited amount from the amino acid tryptophan. However, the ratio reflecting the conversion of tryptophan to niacin is 60:1; thus, the body relies on the diet to provide the majority of niacin necessary for functioning. The term niacin equivalents (NE) is used to express niacin intake recommendations, and it reflects the amount of niacin in our diet and the amount synthesized from tryptophan within the body. The RDA for niacin for adults aged 19 and older is 16 mg/day of NE for men and 14 mg/day of NE for women. Based on NHANES III data, the average dietary intake of niacin from food for men and women between the ages of 19 and 70 years is approximately 27 mg/day and 21 mg/day, respectively.4
What is the primary source of iodine in the diet?
In nature, this element is found primarily as inorganic salts in rocks, soil, plants, animals, and water as either iodine or iodide, but once it enters the GI tract, it is broken down to iodide, which is the negative ion of iodine, designated I-. Upon absorption, the majority of this iodide is taken up by the thyroid gland.
What are consequences of choline deficiency
Inadequate intakes of choline can lead to increased fat accumulation in the liver, which eventually leads to liver damage.
List the primary function(s) of iodine in the body. What does it regulate?
Iodine is the heaviest trace element required for human health and a necessary component of the thyroid hormones, which help regulate human metabolism.
Which of the following b-vitamins are considered to reduce the risk of cardiovascular disease?
Iodine, B6, Folate
List the primary function(s) of vitamin B6 in the body.
(Folate) Amino acid metabolism. Vitamin B6 plays a critical role in transamination, which is a key process in making nonessential amino acids. Without adequate vitamin B6, all amino acids become essential, as our body cannot make them in sufficient quantities. ■ Neurotransmitter synthesis. Vitamin B6 is a coenzyme involved in the synthesis of several neurotransmitters, a process that involves transamination. Neurotransmitters are chemicals necessary for the transmission of nerve impulses across synapses. Because of this, vitamin B6 is important in cognitive function and normal brain activity. Abnormal brain waves have been observed in both infants and adults in vitamin B6 - deficient states. ■ Carbohydrate metabolism. Vitamin B6 is a coenzyme assisting in the breakdown of stored glycogen into glucose. Thus, vitamin B6 plays an important role in maintaining blood glucose during exercise. It is also important for the conversion of amino acids to glucose. ■ Heme synthesis. The synthesis of heme, required for the production of hemoglobin and thus the transport of oxygen in red blood cells, requires vitamin B6. Chronic vitamin B6 deficiency can lead to small red blood cells with inadequate amounts of hemoglobin, which is called microcytic, hypochromic anemia. ■ Immune function. Vitamin B6 plays a role in maintaining the health and activity of lymphocytes and in producing adequate levels of antibodies in response to an immune challenge. The depression of immune function seen in vitamin B6 deficiency may also be due to a reduction in vitamin B6 -dependent enzymes involved in DNA synthesis. ■ Metabolism of other nutrients. Vitamin B6 also plays a role in the metabolism of other nutrients, including niacin, folate, and carnitine.
hyperthyroidism
(high blood levels of thyroid hormone) is most commonly caused by Graves' disease, which is an autoimmune disease that causes an overproduction of thyroid hormones. The symptoms include weight loss, increased heat production, muscular tremors, nervousness, a racing heartbeat, and protrusion of the eyes.
Define Pernicious anemia.
A common culprit in reduced absorption is a condition called pernicious anemia, which is caused by inadequate secretion of intrinsic factor by parietal cells of the stomach.
ariboflavinosis
A condition caused by riboflavin deficiency. Symptoms of ariboflavinosis include sore throat; swelling of the mucous membranes in the mouth and throat; lips that are dry and scaly; a purple-colored tongue; and inflamed, irritated patches on the skin. Severe riboflavin deficiency can impair the metabolism of vitamin B6 (pyridoxine) and niacin.
hypothyroidism
A condition characterized by low blood levels of thyroid hormone.
atrophic gastritis
A condition, frequently seen in people over the age of 50, in which stomach-acid secretions are low.
beriberi
A disease caused by thiamin deficiency, characterized by muscle wasting and nerve damage. Symptoms: fatigue, apathy muscle weakness, and reduced cognitive/cardiovascular functions. Those at greatest risk for poor thiamin status are the elderly, who typically have reduced total energy intakes including people who are physically active (eat simple carbs); anyone with malabsorption syndrome; patients on renal dialysis, since thiamin is easily cleared from the blood during dialysis, people who eat a diet high in unenriched processed grains; and people who abuse alcohol
Pellegra
A disease that results from severe niacin deficiency. Can be identified by the "three Ds"—dermatitis, diarrhea, and dementia.
Who should take folate supplements?
A folate deficiency can cause many adverse health effects, including macrocytic anemia . Pregnant women, the elderly, those at risk for heart problems, and people taking certain medications should take folate supplements
Describe folate's role in neural tube defects and heart disease.
A group of nervous system malformations called neural tube defects are associated with low maternal folate intake. Folate is also essential in the synthesis of new cells, such as the red blood cells, and for the repair of damaged cells. Folate and vitamin B12 are needed for the regeneration of methionine from homocysteine to reduce the risk for CVD.
Intrinsic Factor
A protein secreted by cells of the stomach that binds to vitamin B12 and aids its absorption in the small intestine. The intrinsic factor and vitamin B12-R-binder complexes formed in the stomach pass into the small intestine, where the R-binder protein is hydrolyzed by pancreatic proteolytic enzymes, after which free vitamin B12 binds to the intrinsic factor. The vitamin B12-intrinsic factor complexes are then recognized by receptors on the enterocytes and internalized. These receptors do not recognize vitamin B12 alone but only when it is bound to intrinsic factor. Within the enterocytes, vitamin B12 is released into the cytosol. The vitamin B12 is then released from the enterocyte, bound to a protein called transcobalamin II, and then
List the primary function(s) of mangenese in the body.
A trace mineral, manganese is a cofactor involved in protein, fat, and carbohydrate metabolism, gluconeogenesis, cholesterol synthesis, and the formation of urea, the primary component of urine. It also assists in the synthesis of the protein matrix found in bone tissue and in building cartilage, a tissue supporting joints. Manganese is also an integral component of superoxide dismutase, an antioxidant enzyme. Thus, it assists in the conversion of free radicals to less damaging substances, protecting the body from oxidative damage
Crentism
A unique form of mental retardation that occurs in infants when the mother experiences iodine deficiency during pregnancy.
What are consequences of choline toxicity?
Although small amounts of choline can be synthesized within the body, the amount made is insufficient for our needs; thus, choline is considered an essential dietary nutrient. Choline has an AI of 550 mg/day for men aged 19 and older and an AI of 425 mg/day for women aged 19 and older. There are limited data on the choline intake of North Americans, because choline intake is not reported in the NHANES or other large surveys. In addition, it is not reported in major nutrient databases. However, it is estimated that choline intakes in the United States and Canada range from 730 to 1,040 mg/day4 based on the typical choline content of foods.. Excessive intake of supplemental choline results in various toxicity symptoms, including a fishy body odor, vomiting, excess salivation, sweating, diarrhea, and low blood pressure. The UL for choline for adults 19 years of age and older is 3.5 g/day.
Define dietary folate equivalents (DFE).
Because dietary folate is only half as bioavailable as synthetic folic acid, the amount of food folate in the diet is expressed as dietary folate equivalents, or DFE. In order to calculate the amount of DFE, you need to know that 1 μg of food folate is equal to 0.5 μg of folic acid taken on an empty stomach or 0.6 μg of folic acid taken with a meal. µg of DFE provided in diet = µg of food folate per day + (1.7 × µg of synthetic folic acid/day).
Biotin deficiencies
Biotin deficiencies are typically seen only in people who consume a large number of raw egg whites over long periods of time. This is because raw egg whites contain a protein that binds with biotin and prevents its absorption. Biotin deficiencies are also seen in people fed total parenteral nutrition (nutrients administered by a route other than the GI tract) that is not supplemented with biotin. Symptoms include thinning of hair; loss of hair color; development of a red, scaly rash around the eyes, nose, and mouth; depression; lethargy; and hallucinations.
List the primary function(s) of biotin in the body.
Biotin is a component of four carboxylase enzymes that are present in humans. These enzymes serve as the carbon dioxide (CO2) carrier and the carboxyl donor for substrates. The enzymes that require biotin as a coenzyme are involved in fatty acid synthesis (for example, lipogenesis), gluconeogenesis, and carbohydrate, fat, and protein metabolism.
List the functions of choline in the body.
Choline is a vitamin-like substance that is important for metabolism, the structural integrity of cell membranes, and neurotransmission. It is typically grouped with the B-vitamins because of its role in fat digestion and transport and homocysteine metabolism. Specifically, choline plays an important role in the metabolism and transport of fats and cholesterol. High amounts of the choline-containing compound phosphatidylcholine are found in bile, which aids fat digestion, and in the formation of lipoproteins, which transport endogenous and dietary fat and cholesterol in the blood to the cells. Choline is also necessary for the synthesis of phospholipids and other components of cell membranes; thus, choline plays a critical role in the structural integrity of cell membranes. Finally, choline accelerates the synthesis and release of acetylcholine, a neurotransmitter that is involved in many functions, including muscle movement and memory storage.
Food sources with choline
Choline is widespread in foods, typically in the form of phosphatidylcholine (see Figure 5.6 on page 175) in the cell membranes of the food. The food highest in choline are eggs, while other good sources are milk, liver, soybean oil, salmon, and mushrooms.4,15 Lecithin (a more common term for phosphatidylcholine) is added to foods during processing as an emulsifying agent, which also increases choline intakes in the diet.
List the function of chromium in the body.
Chromium is a trace mineral that plays an important role in carbohydrate metabolism. You may be surprised to learn that the chromium in your body is the same metal used in the chrome plating for cars. Chromium enhances the ability of insulin to transport glucose from the bloodstream into cells. Chromium also plays important roles in the metabolism of RNA and DNA, in immune function, and in growth. Chromium supplements are marketed to reduce body fat and enhance muscle mass and have become popular with bodybuilders and other athletes interested in improving their body composition.
those greatest at risk for riboflavin deficiency
Elderly, people who make poor food choices, those with malabsorption problems; and patients on renal dialysis. Approximately one-third of the RDA for riboflavin is supplied in the American diet by milk and milk products. Riboflavin is destroyed when it is exposed to light; thus, milk is generally stored in opaque containers.
Goiter
Enlargement of the thyroid gland; can be caused by iodine toxicity or deficiency. Goiter, or enlargement of the thyroid gland, occurs with both iodine toxicity and deficiency.
Foods with chromium
Foods identified as good sources of chromium include mushrooms, prunes, dark chocolate, nuts, whole grains, cereals, asparagus, brewer's yeast, some beers, red wine, and meats, especially processed meats. Dairy products are typically poor sources of chromium. Food-processing methods can also add chromium to foods, especially if the food is processed in stainless steel containers. For example, it is assumed that wine and beer derive some of their chromium content from processing.
What are some food sources of vitamin B6? How is it destroyed?
Good sources of vitamin B6 include meat, fish (especially tuna), poultry, and organ meats, which are also high in protein. fish, enriched ready-to-eat cereals, white potatoes and other starchy vegetables, bananas, and fortified soy-based meat substitutes. (40% meat, 60% plant based)
What happens when we consume too much B6
High doses of supplemental vitamin B6 have been associated with sensory neuropathy and dermatological lesions. so the UL has been set for 100 mg/day
Manganese deficiency
Manganese deficiency is rare in humans. Symptoms include impaired growth and reproductive function, reduced bone density and impaired skeletal growth, impaired glucose and lipid metabolism, and skin rash.
Manganese toxicity
Manganese toxicity can occur in occupational environments, such as mines, in which workers inhale manganese dust. It can also result from drinking water high in manganese. Toxicity results in impairment of the neuromuscular system, causing symptoms similar to those seen in Parkinson's disease, such as muscle spasms and tremors. Elevated blood manganese concentrations and neurotoxicity were the criteria used to determine the UL for manganese, which is 11 mg/day for adults 19 years of age and older.
Are minerals organic or inorganic? What is the difference between major and trace minerals?
Minerals are inorganic elements that are not changed by digestion or other metabolic processes.
Trace minerals
Minerals we need to consume in amounts less than 100 mg per day and of which the total amount in our body is less than 5 g (5,000 mg).
Major minerals
Minerals we need to consume in amounts of at least 100 mg per day and of which the total amount in our body is at least 5 g (5,000 mg).
List the primary function(s) of pantothenic acid in the body.
Pantothenic acid is an essential vitamin that is metabolized into two major coenzymes: coenzyme A (CoA) and acyl carrier protein (ACP). Both are essential in the synthesis of fatty acids, while CoA is essential for fatty acid oxidation, ketone metabolism, and the metabolism of carbohydrate and protein. Many of the metabolic reactions that require pantothenic acid for energy production are illustrated in Figure 8.2. Besides its role in energy metabolism, pantothenic acid is required in the synthesis of cholesterol and steroids and in the detoxification of drugs.
How is vitamin B6 involved with heart health?
Reduction in cardiovascular disease (CVD) risk. Vitamin B6, folate, and vitamin B12 are closely interrelated in some metabolic functions, including the metabolism of methionine, an essential amino acid. The body metabolizes methionine to another amino acid, called homocysteine.
Riboflavin (B2)
Reflects its structure and color; ribo refers to the carbon-rich ribityl side chain, and flavin, which is associated with the multiring portion of the vitamin, refers to the yellow color this vitamin produces when dissolved in water. Riboflavin is relatively heat stable but sensitive to light: when exposed to light, the ribityl side chain is cleaved off and the vitamin loses its activity.
Research has consistently shown that individuals with poor B-vitamin status
Research has consistently shown that individuals with poor B-vitamin status
Functions of Riboflavin
Riboflavin is an important component of two coenzymes that are involved in oxidation-reduction reactions occurring within the energy-producing metabolic pathways, including the electron transport chain. These coenzymes, FMN and FAD, are involved in the metabolism of carbohydrates, fatty acids, and amino acids for energy. FAD is also a part of the α-ketoglutarate dehydrogenase complex, which converts α-ketoglutarate to succinate in one step of the TCA cycle. It is also a coenzyme for succinate dehydrogenase, the enzyme involved in the conversion of succinate to fumarate in the next step of the TCA cycle. Finally, riboflavin is a part of the coenzyme required by glutathione peroxidase, which assists in the fight against oxidative damage.
Sulfur functions
Sulfur is a major mineral and a component of the B-vitamins thiamin and biotin. As such, it is essential for macronutrient metabolism. In addition, as part of the amino acids methionine and cysteine, sulfur helps stabilize the three-dimensional shapes of proteins in the body. The liver requires sulfur to assist in the detoxification of alcohol and various drugs, and sulfur helps to maintain acid-base balance.
What is megadosing and why is it harmful?
Taking a dose of a nutrient that is ten or more times greater than the recommended amount. The most toxic vitamins are A and D. It can result in irreversible organ damage and even death.
How much manganese should we eat?
The AI for manganese for adults 19 years of age and older is 2.3 mg/day for men and 1.8 mg/day for women. Manganese requirements are easily met, as this mineral is widespread in foods and is readily available in a varied diet. Whole-grain foods, such as oat bran, wheat flour, whole-wheat spaghetti, and brown rice, are good sources of manganese. Other sources include pineapple, pine nuts, okra, spinach, and raspberries. Overall, grain products contribute approximately 37% of dietary manganese, and vegetables and beverages, primarily tea, contribute another 18% to 20%.
How much folate should we consume
The RDA for folate for adult men and women aged 19 years and older is 400 μg/day, with 600 μg/day required for pregnant women.4 These higher levels of folate were set to minimize the risk for birth defects. The UL for folate is 1,000 μg/day.
How much riboflavin should we consume
The RDA for riboflavin for adults aged 19 years and older is 1.3 mg/day for men and 1.1 mg/day for women, respectively. Based on NHANES III data, the dietary intake of riboflavin from food for men between the ages of 19 and 70 years averages 2.0 to 2.3 mg/day (median = 2 mg/day) and for women of the same age 1.7 to 1.9 mg/day (median = 1.5 mg/day).4
How much thiamin should we eat
The RDA for thiamin for adults aged 19 years and older is 1.2 mg/day for men and 1.1 mg/day for women.
how much B6 should we consume
The RDA for vitamin B6 for adult men and women aged 19 to 50 years is 1.3 mg/day. For adults 51 years of age and older, the RDA increases to 1.7 mg/day for men and 1.5 mg/day for women. Based on NHANES III data, the average dietary intake of vitamin B6 from food for men and women between the ages of 19 and 70 years averages 2 mg/day and 1.5 to 1.6 mg/day, respectively.
Foods with sulfur
The body is able to obtain ample amounts of sulfur from our consumption of protein containing foods; as a result, there is no DRI specifically for sulfur. There are no known toxicity or deficiency symptoms associated with sulfur.
How much chromium should we consume
The body needs only small amounts of chromium. The AI for adults aged 19 to 50 years is 35 μg/day for men and 25 μg/day for women. For adults 51 years of age and older, the AI decreases to 30 μg/day and 20 μg/day for men and women, respectively.17 The AI for individuals over 50 years was based on the energy intake of older adults, which is typically lower than that of younger individuals.
Which water soluble vitamin is stored in the liver?
The body stores vitamin B12 in the liver, approximately 2 to 3 mg, which means we can probably survive for months without vitamin B12 in our diet.4 Vitamin B12 is lost from the system in the urine and bile.
What are potential causes of a vitamin B12 deficiency? What are the symptoms?
The symptoms of anemia include pale skin, diminished energy and exercise tolerance, fatigue, and shortness of breath. Gastrointestinal symptoms include loss of appetite, constipation, excessive gas, and changes in skin pigment.14 Neurologic symptoms include tingling and numbness of extremities, abnormal gait, memory loss, dementia, disorientation, visual disturbances, insomnia, and impaired bladder and bowel control.14 A deficiency of vitamin B12, as with vitamin B6 and folate, has been linked to cardiovascular disease due to high levels of homocysteine.
Functions of niacin
The two forms of niacin, nicotinic acid and nicotinamide, are essential for the formation of the two coenzymes nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). These coenzymes, like those formed from riboflavin and thiamin, are required for the oxidation-reduction reactions involved in the catabolism of carbohydrate, fat, and protein for energy. These coenzymes, like those formed from riboflavin and thiamin, are required for the oxidation-reduction reactions involved in the catabolism of carbohydrate, fat, and protein for energy. Niacin is also an important coenzyme in DNA replication and repair and in the process of cell differentiation. Pharmaceutical preparations of niacin are sometimes prescribed for the treatment of abnormal blood lipids.
Excess biotin
There are no known adverse effects from consuming excess amounts of biotin.
What are some food sources of vitamin B12 and how is it destroyed?
These compounds have cobalt in their center and are surrounded by ring structures. B12 comes almost exclusively from meat, eggs, dairy products, and some seafood and is approximately 50% bioavailable in a typical meal. Fortified plant foods such as soy milks and cereals are also good sources of vitamin. In food, vitamin B12 is bound to protein. It is released from this protein in the acidic environment of the stomach, where it is then attached to another group of proteins called R-binders.
Thiamin
Thiamin was the first B-vitamin discovered, hence its designation as vitamin B1. Thiamin is important in a number of energy-producing metabolic pathways within the body. As a part of TDP, thiamin plays a critical role in the breakdown of glucose for energy. TDP is required for pyruvate dehydrogenase, the enzyme responsible for the conversion of pyruvate to acetyl-CoA. This is a critical step in the conversion of glucose into a smaller molecule that can enter the TCA cycle. Thus, when dietary thiamin is inadequate, the body's ability to metabolize carbohydrate is diminished. Another primary role of TDP is to act as a coenzyme in the metabolism of the branchedchain amino acids, which include leucine, isoleucine, and valine. One of these enzyme complexes helps convert the carbon skeletons of the branched-chain amino acids into products that can enter the TCA cycle, whereas the other converts α-ketoglutarate to succinate in the TCA cycle. Thus, these highly branched amino acids play a significant role in providing fuel for the working muscle, especially during high-intensity exercise. TDP also assists in the production of DNA and RNA, making it important for cell regeneration and protein synthesis. Finally, it plays a role in the synthesis of neurotransmitters
What are potential causes of a folate toxicity and what is a consequence?
Toxicity can occur with high amounts of supplemental folate. One especially frustrating problem with folate toxicity is that it can mask a simultaneous vitamin B12 deficiency.
Vitamin toxicity more typically occurs with supplementation versus food intake.
True
The B-vitamins
act as co-enzymes essential for energy metabolism.
What are some food sources of folate and how is it destroyed?
U.S. Department of Agriculture (USDA) mandated the fortification with folic acid of enriched breads, flours, corn meals, rice, pastas, and other grain products. Other good food sources include liver, spinach, lentils, oatmeal, asparagus, and romaine lettuce. Losses of folate can occur when food is heated or when folate leaches out of cooked foods and the liquid from these foods is discarded.
Functions of B12
Vitamin B12 is part of coenzymes that assist with DNA synthesis, which is necessary for the proper formation of red blood cells. Vitamin B12 is essential for healthy functioning of the nervous system, because it helps maintain the myelin sheath that coats nerve fibers. When this sheath is damaged or absent, the conduction of nerve signals is altered, causing numerous neurologic problems. Adequate levels of vitamin B12 and folate, as well as B6, are also necessary for the metabolism of the amino acid homocysteine, which we discussed earlier.
How is vitamin B12 absorbed by the body?
Vitamin B12 is synthesized almost entirely by bacteria in animals.
How do micronutrients help metabolism?
Vitamins and minerals are not direct sources of energy, but they help generate energy from carbohydrates, fats, proteins, and alcohol. Some micronutrients promote energy metabolism by facilitating the transport of nutrients into the cells.
Fat-soluble minerals
Vitamins that are not soluble in water but soluble in fat. These include vitamins A, D, E, and K.
Water-soluble minerals
Vitamins that are soluble in water. These include vitamin C and the B-vitamins.
Folate and folic acid functions
Within the body, folate functions primarily in association with folate-dependent coenzymes that act as acceptors and donors of one-carbon units. These enzymes are critical for DNA synthesis, cell differentiation, and amino acid metabolism, which occur within the cytosol, nucleus, and mitochondria of the cells. Folate's role in assisting with cell division makes it a critical nutrient during the first few weeks of pregnancy, when the combined sperm- egg cell multiplies rapidly to form the primitive tissues and structures of the human body.
What are some scenarios that may lead to a vitamin B6 deficiency?
alcoholism, certain prescription medications, intense physical activity, and chronic diseases, such as arthritis and vascular disease. If we don't get enough vitamin B6 in the diet, the symptoms of vitamin B6 deficiency can develop. These include anemia, convulsions, depression, confusion, and inflamed, irritated patches on the skin. Notice that the symptoms associated with vitamin B6 deficiency involve three tissues: skin, blood, and the nervous system.
How is pantothenic acid destroyed?
easily destroyed by food processing
Adequate folate intake is essential during early pregnancy because
folate is critical for cell division.
What are some food sources of thiamin? How is it destroyed and how can it be conserved?
ham and other pork products (Figure 8.4, on page 310). Sunflower seeds, beans, oat bran, mixed dishes that contain whole or enriched grains and meat, tuna fish, soy milk, and soy-based meat substitutes are also good sources. Enriched and whole-grain foods, including fortified ready-to-eat cereals, are rich in several B-vitamins, including thiamin.
What is niacin flush?
however, niacin can cause toxicity symptoms when taken in supplement form. These symptoms include flushing, which is burning, tingling, and itching sensations accompanied by a reddened flush, primarily on the face, arms, and chest. Liver damage, glucose intolerance, blurred vision, and edema of the eyes can be seen with very large doses of niacin taken over long periods of time. The UL for niacin is 35 mg/day and was determined based on the level of niacin below which flushing is typically not observed.
Four minerals also function in energy metabolism:
the trace minerals iodine, chromium, and manganese, and the major mineral sulfur. •
Important B vitamins
thiamin, riboflavin, vitamin B6, niacin, folate, vitamin B12, pantothenic acid, and biotin., which all act as coenzyme.s Acting as coenzymes, micronutrients such as the B-vitamins assist enzymes in metabolizing macronutrients to produce energy. Minerals such as chromium and iodine assist with nutrient uptake into the cells and with regulating energy production and cell growth. TTP breaks down glucose. Riboflavin is a part of two coenzymes, flavin mononucleotide (FMN) and flavin adenine dinucleotide (FAD), which help break down glucose and fatty acids.