In this presentation, we're going to focus on the second part of the vitamins and minerals, those that are related to vision and energy metabolism. Just as a reminder, micronutrients can function in a variety of ways. We've already taken a look at those that are related to fluid balance and that behave as antioxidants. We're going to look now at those that are related to vision and energy metabolism. And the last video will look at bone health and blood health. Our first vitamin is vitamin A, and vitamin A is a fat soluble vitamin that is technically a group of chemically related molecules in our bodies. We store it in the liver and a little bit in our adipose tissue. Retinoids are the forms of vitamin A that are found in animals, and there are three major active forms retinols, retinols, and retinoic acid. You may have heard the term retinol before, because it's a frequent ingredient in anti-aging products that people put on their skin.
Carotenoids refer to a large group of plant molecules that have a variety of functions in plants, but among the carotenoids are beta carotene and alpha carotene. Beta carotene is the most abundant and important that acts as a precursor called a provtamin for vitamin A, so when we eat plant sources of vitamin A with high in beta carotene like carrots or pistachios, that beta carotene gets chopped in half effectively and becomes two retinol molecules the forms that are available and active in animals.
Vitamin A plays a particularly important role in relation to our vision. It combines with a protein in our eyes called opsin to form something called rhodopsin, which help us to see in low light as well as to have some aspects of our color vision. It also helps to maintain the fluidity and sort of gel like property of our cornea, which is the protective covering of our iris and pupil in our eyes. When we have a vitamin A deficiency, one of the outcomes could be keratinosis, which is basically a hardening of our corneas. Other functions that vitamin A has, in addition to its roles in our vision is the maintenance of epithelial tissues, particularly the cells that line our mucous membranes and our skin. It also plays a role in immunity.
Vitamin A is needed in very, very, very small amounts. 900 micrograms per day for biological males and 700 micrograms per day in biological females. You might see it written on vitamin bottles as R.A.E. instead of the units of micrograms, and what R.A.E. stands for is retinol activity equivalence. And this is because there's so many different molecular forms that each have their own level of bioactivity. That really is basically a conversion factor that allows us to understand the active amount of vitamin A we get from that particular source. Good sources of vitamin A from animals are things like liver, tuna, fortified dairy and dairy substitutes, and plants, leafy greens, sweet potatoes, carrots and mango. Vitamin A deficiency is called hypovitaminosis A minuses A it results in impaired immunity, night blindness, and ultimately, corneal degeneration and blindness. So you can see this is a person. with normal vision, and this is a person who suffers from night blindness due to a vitamin A deficiency. In addition, sometimes in little children, they may eat too many carrots, or other sources like sweet potatoes. And the beta carotene will deposit in the fat of your hands and your feet. This, in and of itself, is not dangerous, so I wouldn't worry about it, but it can give sort of a weird look to your child when they turn orange.
Its toxicity, comes with itchy skin, appetite loss, dizziness, nausea and joint pain. Severe toxicity is extremely rare but can lead to coma and death. And one thing to be aware of is during pregnancy is you really need to be careful about taking any extra vitamin A or even using the retinol creams on your skin, because it can be absorbed into your body and can lead to birth defects in the fetus.
Micronutrients that are involved in regulating metabolism are going to be either cofactors or Co- enzymes. I just want to take a moment to remind you that enzymes are generally proteins that function to help chemical reactions happen at a rate that's fast enough for life to exist. Many enzymes need little helpers to to do that. And so this is where cofactors and coenzymes come in. Cofactors are the mineral helpers and coenzymes are the vitamin helpers. So cofactors are inorganic mineral sources and coenzymes are organic from the chemistry sense, vitamin sources. And you can see in this graphic that here's the active site on the enzyme. And the molecule that needs to bind there cannot bind because it doesn't match shapes. But if you have the cofactor then it can bind just fine.
These are the vitamins and minerals that act as coenzyme and cofactors. All of the B vitamins. So B1, B2, B3, B5, B6, B7, B9, and B12 all are involved as Co enzymes in various aspects of metabolism.
Whereas the mineral ones iodine, manganese, sulfur, chromium and molybdenum all behave as co-factors. They're used over and over again, just like an enzyme is not affected by the number of reactions that it catalyzes. These coenzymes and cofactors will be used over and over again, which is why we do not need to consume them in very large amounts. Our first vitamin B vitamin that we're going to look at is thiamin, which is also known as vitamin B1. It's needed, uh, in biological men at about 1.2mg per day and women at 1.1mg per day.
Is chief functions in the body or to assist with glucose metabolism. So basically breaking down glucose and also with the synthesis of RNA, DNA and ATP. Good sources include legumes. So beans, peas, things like that. Pork, fish, whole grains, and fortified sources like breads and rice.
Thiamin deficiency. There's two forms of the deficiency disease. One is called Beriberi, and this occurs when people do not have adequate vitamin thiamin in their diets. And Wernicke-Korsakoff is a disease that is seen in alcoholics where they have malabsorption of the thiamin vitamin. The symptoms include an enlarged heart, cardiac failure, muscular weakness, apathy, short term memory loss, confusion, irritability, anorexia, and weight loss. And toxicity symptoms are there aren't any. There is no known toxicity for thiamin.
Our second be vitamin is riboflavin or B2. Also needed about 1.3mg per day for biological males and 1.1mg per day for biological females. The chief functions in the body are to assist in carbohydrate and fat metabolism, that is, the breakdown and rebuilding of carbohydrates and fats. Good sources include liver, lean beef and pork, mushrooms, almonds, spinach, fortified cereals and breads, and milk and yogurt.
Riboflavin deficiency is called Ariboflavonosis. Symptoms include inflamed eyelids and sensitivity to light and a reddening of the cornea, sore throat, cracks and redness at the corners of the mouth, painful, smooth purplish red tongue and inflammation characterized by skin lesions covered with greasy scales like you can see here in this picture. There are no known toxicity symptoms for riboflavin. Niacin or B3 is needed in slightly larger amounts. 60mg of niacin equivalents a day versus, for biological males versus 14mg of Niacin equivalents per day for biological females. Niacin works as a coenzyme in over 400 enzymes in our body. So without niacin in our diets, we have a lot of problems with function. It's involved in glucose, fat and protein metabolism. It repairs DNA and it can actually also act as an antioxidant. Good sources include meat, fish, brown rice, nuts and seeds, legumes, and bananas. One thing I will note, niacin is frequently added to energy drinks because it does have a stimulant effect. So it's one of the multiple compounds that are added to things like Red Bull in order to provide that jittery feeling that you get when you consume those, you do need to. It toxicity is uncommon, but you should just be aware that maybe you don't need to be consuming those energy drinks. They're not a good source of niacin. Okay. The deficiency disease is called pellagra, and it's usually occurs in people with severe malnutrition or when the diet includes a lot of corn and that corn hasn't been nixtamalized So basically corn is very high in niacin, but it's bound up to carbohydrates., so our bodies cannot absorb it unless that corn has been treated with calcium hydroxide, cooked, ground, which is what happens in the process of tortilla making. And then because of that treatment, it becomes, absorbable. We also see niacin deficiencies in alcoholics. The symptoms of niacin deficiency are, sometimes frequently called the Four D's: diarrhea, dermatitis, dementia and death. A person with a niacin deficiency is going to show an inflamed, swollen, smooth, bright red tongue may suffer from depression, apathy, fatigue, loss of memory, and headaches.
Toxicity can also occur. You'll get flushed, hives, a rash, potentially excessive sweating, blurred vision. and if it's truly [excess], the excessive then it can be liver damage and impair your glucose tolerance. B5, also known as pantothenic acid, is needed, in all adults in this same amount. Five milligrams per day. And if you are pregnant or lactating, then you want to take slightly higher amounts or have slightly higher amounts in your diet. The two functions are is a part of what's called coenzyme A, which is used in the process of cellular respiration and energy metabolism in our mitochondria. And, pantothenic acid is also important for breaking down fats. Good sources include mushrooms, meats, dairy, nuts and seeds. Avocados, brown rice, and oats. Deficiency and toxicity are pretty rare. Vitamin B6. Is needed based on age. So it's needed in 19 to 50 year olds in about 1.3mg per day, and in people over the age of 51, one and a half to 1.7mg per day.
It's chief functions are to act as a coenzyme in amino acid and fatty acid metabolism. So the breakdown in building of amino acids and fatty acids. It also helps to convert tryptophan to niacin another B vitamin, as well as to serotonin which is a neurotransmitter. Vitamin B6 is also significant in its, importance in making red blood cells. Good sources include liver, fatty fish, fortified grains, chickpeas, and, which are also known as garbanzo beans, leafy greens, oranges, and cantaloupe. Deficiency and toxicity are rare. Vitamin B7 or biotin has only an adequate intake number, which is 30 micrograms per day. It is very widespread in foods. And its chief function is as a coenzyme in energy metabolism, fat synthesis, amino acid metabolism, and glycogen synthesis. Good sources are organ meats, egg yolks, soybeans, fish, and whole grains.
Biotin is often sold and marketed as something for healthy skin and hair, healthy skin, hair, and nails. There is absolutely no research to support this, so I probably would not, rely on taking biotin for that reason.
Deficiency and toxicity are rare.
Folate, or vitamin B9, has, uh. RDA of 400 micrograms per day of fully equivalence dietary folate equivalence. And if you're pregnant or lactating, that number goes up to 600 to 500 micrograms per day.
Chief function in the body is it's part of a coenzyme used in the synthesis of DNA. So it's very important in making new cells. So for example, in a developing fetus uh a lot of folic acid is needed, which is the biologically active form of folate, in order for the fetus to develop properly. It's also a coenzyme for the synthesis of some of our amino acids. Good sources of folate are fortified grains, leafy green vegetables, legumes and seeds and liver. It's added to food as folic acid, which is a form of the molecule that's more easily absorbed from food sources. Deficiencies can include macrocytic anemia, which is occurs when cells cannot divide normally. So our red blood cells in particular are too large and do not have as much hemoglobin in them, so they're not very efficient at carrying oxygen. The other common deficiency outcome is spinal bifida, which is where a person suffers from what are called neural tube defects. The spine does not enclose the spinal cord. So the spinal cord bulges out. And this can happen anywhere along the spinal cord and will affect the individual differently depending on where it, where that defect occurs.
When the relationship between folic acid and spider bifida was discovered, we began to increase the fortification of folic acid into cereals and breads and other grain type products. And this seems to have had a pretty positive effect in greatly lowering the rates of spinal bifida in the United States. Vitamin B12. Our last B vitamin is needed in very minuscule amounts, 2.4 micrograms per day. And its chief functions in the body is its part of the coenzyme is used in new cell synthesis, including red blood cells. It helps in the development and maintenance of nerve cells. And it reforms the folate coenzyme. So vitamin B12 and folate often need be together. And it also helps break down some of the fatty acids and amino acids. Vitamin B12 deficiency symptoms include fatigue, degeneration of peripheral nerves that may progressed to paralysis, memory loss, and dementia. Deficiency is much more common in vegans and vegetarians because. B12 is most abundant and easily absorbed from animal products. So vegans and vegetarians may want to evaluate their diet, and this is one place where supplementation may be required because there are not good sources, especially for vegans. If some of you may have heard that brewer's yeast is a good option, but it has to be brewer's yeast that has been fortified with B12. Otherwise, just taking brewer's eating brewer's yeast is not going to do it.
Some individuals may also suffer from what's called Megaloblastic anemia. And this is where again, similar to what happens in folate, deficiency is you have oversized red blood cells with less hemoglobin, so they're not very efficient at transporting oxygen. There's an autoimmune disease called pernicious anemia, which is where people cannot absorb the B12 because they lack certain factors, which are proteins to do. So. When you take medicines for GERD and ulcers like, proton pump inhibitors, for example, those can block the absorption of B12. And for Type 2 diabetics using metformin - that can also inhibit the absorption of vitamin B12. There are no known toxicity symptoms for vitamin B12.
Now the mineral cofactors! Iodine is needed in very small amounts, about 150 micrograms per day. Its primary function is as a component of the two thyroid hormones that help regulate growth, development, and metabolic rates. Good sources are seaweed, shellfish, and some other fish like cod or canned tuna, dairy and eggs. So again, if you're a vegan, you want to make sure that you're getting access by eating seaweed or iodized salt. Again, like with folic acid, the reason why we add iodine to salt is to try [and} on a population scale to lower the risks of iodine deficiency. Iodine deficiency.
cccurs when people have an underactive thyroid gland and are not making adequate, um, thyroid hormones. This can create what's called a goiter, which is a very enlarged version of the thyroid gland. Essentially, the thyroid gets bigger and bigger in the hopes of finding any iodine that may be passing through until ultimately it stops working altogether. Cretinismis a potential other outcome of hypothyroid hypothyroidism, where a person will have growth impairment, both mental and physical growth impairment. And yeah, toxicity can be an overactive thyroid gland basically making too much thyroid hormones. And this also interestingly results in a greater.
Manganese and molybdenum are two micronutrients that are needed in minuscule amounts, and they both function in, uh, as cofactors for glucose synthesis and amino acid metabolism. And chromium is found - only has an adequate intake of minuscule amounts as well. It is very significant in its function in helping insulin talk to cells, to tell them to take up glucose, and in the metabolisms of lipids and proteins. So the breaking down and rebuilding of lipids and proteins. Good sources are meats, mushrooms, some spices interestingly eggs, whole grains and again brewer's yeast. The amount of chromium in food varies by the amount of chromium in the soil where the food is grown, because the plants take up the chromium from the soil. Some of you also may have heard that, there's a very toxic form of chromium that is not this version of chromium. It's a different compound, so you don't need to worry about it for your diet.
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