This is because a protein in egg whites tightly binds to biotin making it unavailable for absorption. A rare genetic disease-causing malfunction of the biotinidase enzyme also results in biotin deficiency.
Biotin deficiency is very rare and deficiency symptoms are similar to those of other B vitamins such as weakness, but may also include hair loss when severe, a rash around the eyes, nose and mouth, depression, lethargy and hallucinations.
People at risk of developing a biotin deficiency include individuals who eat a lot of raw egg whites the uncooked protein binds biotin making it unavailable for absorption , and patients receiving total parental nutrition. Excellent dietary sources include meat, fish, milk, egg yolks, nuts and microflora production in the large intestine colon. Therefore, rapidly dividing cells are most affected by folate deficiency.
Red blood cells, white blood cells, and platelets are continuously being synthesized in the bone marrow from dividing stem cells. A consequence of folate deficiency is macrocytic, also called megaloblastic, anemia.
Macrocytic anemia is characterized by larger and fewer red blood cells. It is caused by red blood cells being unable to produce DNA and RNA fast enough—cells grow but do not divide, making them large in size.
Folate is especially essential for the growth and specialization of cells of the central nervous system. Children whose mothers were folate-deficient during pregnancy have a higher risk of neural-tube birth defects. Folate deficiency is causally linked to the development of spina bifida, a neural-tube defect that occurs when the spine does not completely enclose the spinal cord.
Spina bifida can lead to many physical and mental disabilities Figure 6. Observational studies show that the prevalence of neural-tube defects was decreased after the fortification of enriched cereal grain products with folate in in the United States and in Canada compared to before grain products were fortified with folate Figure Additionally, results of clinical trials have demonstrated that neural-tube defects are significantly decreased in the offspring of mothers who began taking folate supplements one month prior to becoming pregnant and throughout the pregnancy.
Some were concerned that higher folate intakes may cause colon cancer, however scientific studies refute this hypothesis. Cobalamin contains cobalt, making it the only vitamin that contains a metal ion. Cobalamin is an essential part of coenzymes. It is necessary for fat and protein catabolism, for folate coenzyme function, and for hemoglobin synthesis. An enzyme requiring cobalamin is needed by a folate-dependent enzyme to synthesize DNA.
Thus, a deficiency in cobalamin has similar consequences to health as folate deficiency. In children and adults cobalamin deficiency causes macrocytic anemia, and in babies born to cobalamin-deficient mothers, there is an increased risk of neural-tube defects. In order for the human body to absorb cobalamin, the stomach, pancreas, and small intestine must be functioning properly. Cells in the stomach secrete a protein called intrinsic factor that is necessary for cobalamin absorption, which occurs in the small intestine.
Impairment of secretion of this protein either caused by an autoimmune disease or by chronic inflammation of the stomach such as that occurring in some people with H. Vitamin B 12 malabsorption is most common in the elderly, who may have impaired functioning of digestive organs, a normal consequence of aging. Pernicious anemia is treated with large oral doses of vitamin B 12 or by putting the vitamin under the tongue, where it is absorbed into the blood stream without passing through the intestine.
In patients that do not respond to oral or sublingual treatment, vitamin B 12 is given by injection. Although some marketers claim taking a vitamin that contains one-thousand times the daily value of certain B vitamins boosts energy and performance, this is a myth that is not backed by science. As discussed, B vitamins are needed to support energy metabolism and growth, but taking in more than required does not supply you with more energy. A great analogy of this phenomenon is the gas in your car.
Does it drive faster with a half-tank of gas or a full one? It does not matter; the car drives just as fast as long as it has gas. Similarly, depletion of B vitamins will cause problems in energy metabolism, but having more than is required to run metabolism does not speed it up.
Buyers of B-vitamin supplements beware; B vitamins are not stored in the body and all excess will be flushed down the toilet along with the extra money spent. B vitamins are naturally present in numerous foods, and many other foods are enriched with them. In the United States, B-vitamin deficiencies are rare; however, in the nineteenth century, some vitamin-B deficiencies plagued many people in North America.
Niacin deficiency, also known as pellagra, was prominent in poorer Americans whose main dietary staple was refined cornmeal Video 6. Its symptoms were severe and included diarrhea, dermatitis, dementia, and even death. Review this video on how Dr. Joseph Goldberger discovered that pellagra was a diet-related illness. B vitamins are water-soluble and are not stored in significant amounts in the body.
Therefore, they must be continuously obtained from the diet. Fortunately, B vitamins are generally well-absorbed in the gut. It should be noted that B vitamins are lost from foods during storage, processing, and cooking. To maximize B vitamin uptake, fruits and vegetables should not be stored for long periods of time, should be eaten more as whole foods, and vegetables should be steamed rather than boiled.
Also, alcohol disrupts intestinal absorption of B vitamins. The US Department of Agriculture has reports of the nutrient contents in foods, including all B vitamins, available at their website. Source: Institute of Medicine. June 12, The USDA has an interactive database of nutrient contents in food. To view reports of single nutrients simply click on the one you are interested in and view the report.
To assist you in getting all the vitamin B 12 and folate you need to support metabolism and blood cell synthesis look over Table 6. There is emerging evidence that vitamin K may play a role in energy metabolism, but currently, the exact functions of vitamin K-dependent enzymes in energy metabolism remain elusive. Vitamin K is required for optimal bone metabolism. Most users should sign in with their email address. If you originally registered with a username please use that to sign in.
To purchase short term access, please sign in to your Oxford Academic account above. Don't already have an Oxford Academic account? Oxford University Press is a department of the University of Oxford.
It furthers the University's objective of excellence in research, scholarship, and education by publishing worldwide. Sign In or Create an Account. Sign In. Advanced Search. Search Menu. Article Navigation. Close mobile search navigation Article Navigation. Volume 1. Assists in carbohydrate and fat metabolism. Niacin B 3. Assists in glucose, fat, and protein metabolism. Pantothenic Acid B 5. Assists in glucose, fat, and protein metabolism, cholesterol and neurotransmitter synthesis.
Assists in the breakdown of glycogen and synthesis of amino acids, neurotransmitters, and hemoglobin. Biotin B 7. Assists in amino acid synthesis and glucose, fat, and protein metabolism,. Folate B 9. Protects nerve cells and assists in fat and protein catabolism, folate function, and red blood cell synthesis.
Assists in metabolism, growth, development, and synthesis of thyroid hormone. Assists in carbohydrate and cholesterol metabolism, bone formation, and the synthesis of urea. A component in sulfur-containing amino acids necessary in certain enzymes; a component in thiamin and biotin. Vitamins and minerals involved in energy metabolism and the role they each play. Because B vitamins play so many important roles in energy metabolism, it is common to see marketing claims that B vitamins boost energy and performance.
This is a myth that is not backed by science. As discussed, B vitamins are needed to support energy metabolism and growth, but taking in more than required does not supply you with more energy.
A great analogy of this phenomenon is the gas in your car. Does it drive faster with a half-tank of gas or a full one? It does not matter; the car drives just as fast as long as it has gas. Similarly, depletion of B vitamins will cause problems in energy metabolism, but having more than is required to run metabolism does not speed it up.
And because B vitamins are water-soluble, they are not stored in the body and any excess will be excreted from the body, essentially flushing out the added expense of the supplements. The B vitamins important for energy metabolism are naturally present in numerous foods, and many other foods are enriched with them; therefore, B vitamin deficiencies are rare.
Similarly, most of the minerals involved in energy metabolism and listed above are trace minerals that are not frequently deficient in the diet. However, when a deficiency of one of these vitamins or minerals does occur, symptoms can be seen throughout the body because of their relationship to energy metabolism, which happens in all cells of the body. A lack of these vitamins and minerals typically impairs blood health and the conversion of macronutrients into usable energy i.
Deficiency can also lead to an increase in susceptibility to infections, tiredness, lack of energy, and a decrease in concentration. Because of their water-solubility, toxicities of most of these nutrients are also uncommon, as excess intake is often excreted from the body. Large quantities, particularly through supplements, can lead to adverse side effects or cause interactions with medications.
For example, too much niacin can cause flushing of the skin or dangerous drops in blood pressure, and a high intake of B 6 can lead to neuropathy. When taking vitamin or mineral supplements, always pay attention to the recommended dietary allowance and avoid exceeding the tolerable upper intake level UL. Therefore, rapidly dividing cells are most affected by folate deficiency. Red blood cells, white blood cells, and platelets are continuously being synthesized in the bone marrow from dividing stem cells.
When folate is deficient, cells cannot divide normally. A consequence of folate deficiency is macrocytic anemia. Macrocytic anemia is characterized by larger and fewer red blood cells that are less efficient at carrying oxygen to cells. It is caused by red blood cells being unable to produce DNA and RNA fast enough—cells grow but do not divide, making them large in size. Folate is especially essential for the growth and specialization of cells of the central nervous system.
Children whose mothers were folate-deficient during pregnancy have a higher risk of neural tube birth defects. Folate deficiency is causally linked to the development of spina bifida, a neural tube defect that occurs in a developing fetus when the spine does not completely enclose the spinal cord.
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