Vitamin B3

Vitamin B3 is one of 8 B vitamins, all of which are water-soluble, meaning that the body does not store them. It is also known as niacin (nicotinic acid) and has 2 other forms, niacinamide (nicotinamide) and inositol hexanicotinate, which have different effects from niacin.

envision-optical-gold-coast-tuna-filletAll B vitamins help the body to convert carbohydrates into fuel (glucose), which is used to produce energy. These B vitamins, often referred to as B complex vitamins, also help the body use fats and protein.

B complex vitamins are needed for healthy skin, hair, eyes, and liver. They also help the nervous system function properly.

Niacin also helps the body make various sex and stress related hormones in the adrenal glands and other parts of the body as well as improve circulation.

In the United States, alcoholism is the main cause of vitamin B3 deficiency. Symptoms of mild deficiency include indigestion, fatigue, canker sores, vomiting, and depression. Severe deficiency can cause a condition known as pellagra. Pellagra is characterized by cracked, scaly skin, dementia, and/or diarrhea. It is generally treated with a nutritionally balanced diet and niacin supplements. Niacin deficiency also causes burning in the mouth and a swollen, bright red tongue.

Medical grade and high doses of B3 have been studied to prevent or improve symptoms of the following conditions.

FOOD SOURCES

The best food sources of vitamin B3 are found in beets, brewer’s yeast, beef liver, beef kidney, fish, salmon, swordfish, tuna, sunflower seeds, and peanuts. In addition, foods that contain tryptophan, an amino acid the body coverts into niacin with the help of vitamin B6, include poultry, red meat, eggs, and dairy products.

BEST AS SUPPLEMENT

Vitamin B3 as niacin, niacin USP, and inositol hexaniacinate. Niacin is available as a tablet or capsule in both regular and timed-release forms. The timed-release tablets and capsules may have fewer side effects than regular niacin. However, the timed-release versions are more likely to cause liver damage if taken at high doses for long periods of time. Regardless of which form of niacin you’re using, doctors recommend periodic liver function tests when using high doses (above 100 mg per day) of niacin.

INTERACTIONS WITH MEDICATIONS

High doses (50 mg or more) of niacin can cause side effects. The most common side effect is called “niacin flush,” which is a burning, tingling sensation in the face and chest, and red or flushed skin.

People with a history of liver disease, kidney disease, or stomach ulcers should not take niacin supplements. Those with diabetes or gallbladder disease should do so only under the close supervision of their doctor.

Stop taking niacin at least two weeks before a scheduled surgery.

Niacin may make allergies worse by increasing histamine.

People with low blood pressure should not take niacin because it may cause a dangerous drop in blood pressure. Don’t take niacin if you have a history of gout.

People with coronary artery disease or unstable angina should not take niacin without their doctor’s supervision, as large doses can raise the risk of heart rhythm problems.

Taking any one of the B vitamins for a long period of time can result in an imbalance of other important B vitamins. For this reason, you may want to take a B complex vitamin, which includes all the B vitamins.

If you are currently taking any of the following medications, you should not use niacin without first talking to your health care provider.

Antibiotics, Tetracycline — Niacin should not be taken at the same time as the antibiotic tetracycline because it interferes with the absorption and effectiveness of this medication. All vitamin B complex supplements act in this way and should be taken at different times from tetracycline.

Anti-seizure Medications — Phenytoin (Dilantin) and valproic acid (Depakote) may cause niacin deficiency in some people. Taking niacin with carbamazepine (Tegretol) or mysoline (Primidone) may increase levels of these medications in the body.

Anticoagulants (blood thinners) — Niacin may make the effects of these medications stronger, increasing the risk of bleeding.

Blood Pressure Medications, Alpha-blockers — Niacin can make the effects of medications taken to lower blood pressure stronger, leading to the risk of low blood pressure.

Cholesterol-lowering Medications — Niacin binds the cholesterol lowering medications known as bile-acid sequestrants and may make them less effective. For this reason, niacin and these medications should be taken at different times of the day. Bile-acid sequestrants include colestipol (Colestid), colesevelam (Welchol), and cholestyramine (Questran).

Statins — Some scientific evidence suggests that taking niacin with simvastatin (Zocor) appears to slow down the progression of heart disease. However, the combination may also increase the likelihood for serious side effects, such as muscle inflammation or liver damage.

Diabetes Medications — Niacin may increase blood sugar levels. People taking insulin, metformin (Glucophage), glyburide (Dibeta, Micronase), glipizide (Glucotrol), or other medications used to treat high blood glucose levels should monitor their blood sugar levels closely when taking niacin supplements.

Isoniazid (INH) — INH, a medication used to treat tuberculosis, may cause a niacin deficiency.

Nicotine Patches — Using nicotine patches with niacin may worsen or increase the risk of flushing associated with niacin.

These medications may lower levels of niacin in the body:

  • Azathioprine (Imuran)
  • Chloramphenicol (Chloromycetin)
  • Cycloserine (Seromycin)
  • Fluorouracil
  • Levodopa and carbidopa
  • Mercaptopurine (Purinethol)

SUPPORTING REFERENCES

Goldberg A, Alagona P, Capuzzi DM, et al. Multiple-dose efficacy and safety of an extended-release form of niacin in management of hyperlipidemia. Am J Cardiol. 2000;85:1100-1105.

Jacques PF, Chylack LT Jr, Hankinson SE, et al. Long-term nutrient intake and early age related nuclear lens opacities. Arch Ophthalmol. 2001;119(7):1009-1019.

Nutrients and Nutritional Agents. In: Kastrup EK, Hines Burnham T, Short RM, et al, eds. Drug Facts and Comparisons. St. Louis, Mo: Facts and Comparisons; 2000:4-5.

Raja R, Thomas JM, Greenhill-Hopper M, Ley SV, Almeida Paz FA. Facile, one-step production of niacin (vitamin B3) and other nitrogen-containing pharmaceutical chemicals with a single-site heterogeneous catalyst. Chemistry. 2008;14(8):2340-8.

Sanyal S, Karas RH, Kuvin JT. Present-day uses of niacin: effects on lipid and non-lipid parameters. Expert Opin Pharmacother. 2007 Aug;8(11):1711-7.

Torkos S. Drug-nutrient interactions: a focus on cholesterol-lowering agents. Int J Integrative Med. 2000;2(3):9-13.

Wolerton: Comprehensive Dermatalogic Drug Therapy, 2nd ed. Philadelphia, PA: Saunders Elsevier. 2007.

Vitamin B2

Vitamin B2, also called riboflavin, is one of the 8 B vitamins. All the B vitamins are water-soluble, meaning that the body does not store them.

vitaminb2All B vitamins help the body convert food (carbohydrates) into fuel (glucose), which is “burned” to produce energy. These B vitamins, often referred to as B complex vitamins, also help the body metabolize fats and protein. B complex vitamins are necessary for healthy skin, hair, eyes, and liver. They also help the nervous system function properly.

In addition to producing energy for the body, riboflavin also works as an antioxidant by fighting damaging particles in the body known as free radicals. Free radicals can damage cells and DNA, and may contribute to the aging process, as well as the development of a number of health conditions, such as heart disease and cancer. Antioxidants such as riboflavin can fight free radicals and may reduce or help prevent some of the damage they cause.

Riboflavin is also needed to help the body change vitamin B6 (pyridoxine) and B9 (folate) into forms it can use. It is also important for body growth and red blood cell production. Most healthy people who eat a well-balanced diet get enough riboflavin. However, elderly people and alcoholics may be at risk for riboflavin deficiency because of poor diet. Symptoms of riboflavin deficiency include fatigue; slowed growth; digestive problems; cracks and sores around the corners of the mouth; swollen magenta-colored tongue; eye fatigue; swelling and soreness of the throat; and sensitivity to light.

FOOD SOURCES

The best sources of riboflavin include brewer’s yeast, hard goat cheese, almonds, organ meats, whole grains, wheat germ, wild rice, mushrooms, yogurt, eggs, broccoli, Brussels sprouts, and spinach.

Riboflavin is destroyed by light, so food should be stored away from light to protect its content. While it is not destroyed by heat, it can be lost in water when foods are boiled or soaked. During cooking, roasting, and steaming it preserves more riboflavin than any kind of frying.

BEST AS SUPPLEMENT

It is best provided as riboflavin itself and no other identity. It is generally included in multivitamins and B-complex vitamins, and comes separately in 25-, 50-, and 100-mg tablets. Some medical grade riboflavin can be provided as high as 400mg in one capsule.

INTERACTIONS WITH MEDICATIONS

If you are currently being treated with any of the following medications, you should not use vitamin B2 supplements without first talking to your health care provider.

Anticholinergic Drugs – used to treat a variety of conditions, including gastrointestinal spasms, asthma, depression, and motion sickness. These drugs may make it hard for the body to absorb riboflavin.

Tetracycline – Riboflavin interferes with the absorption and effectiveness of tetracycline, an antibiotic. All vitamin B complex supplements act in this way. You should take riboflavin at a different time during the day from when you take tetracycline.

Tricyclic Antidepressants – Tricyclic antidepressants may reduce levels of riboflavin in the body. They include:
Imipramine (Tofranil)
Desimpramine (Norpramin)
Amitriptyline (Elavil)
Nortriptyline (Pamelor)

Antipsychotic Medications – Antipsychotic medications called phenothiazines (such as chlorpromazine or Thorazine) may lower riboflavin levels.

Doxorubicin – Riboflavin interferes with doxorubicin, a medication used for the treatment of certain cancers. Also, doxorubicin may deplete levels of riboflavin in the body. Your doctor will let you know whether you need to take a riboflavin supplement or not.

Methotrexate – Methotrexate, a medication used to treat cancer and autoimmune diseases such as rheumatoid arthritis, can interfere with how the body uses riboflavin.

Phenytoin – Phenytoin (Dilantin), a medication used to control seizures, may affect riboflavin levels in the body.

Probenecid – This medication used for gout may decrease the absorption of riboflavin from the digestive tract and increase how much is lost in the urine.

Thiazide Diuretics (water pills) – Diuretics that belong to a class known as thiazides, such as hydrochlorothiazide, may cause you to lose more riboflavin in your urine.

SUPPORTING REFERENCES

Antoon AY, Donovan DK. Burn Injuries. In: Behrman RE, Kliegman RM, Jenson HB, eds. Nelson Textbook of Pediatrics. Philadelphia, Pa: W.B. Saunders Company; 2000:287-294.

Bruno EJ Jr, Ziegenfuss TN. Water-soluble vitamins: research update. Curr Sports Med Rep. 2005 Aug;4(4):207-13. Review.

Fishman SM, Christian P, West KP. The role of vitamins in the prevention and control of anaemia. [Review]. Public Health Nutr. 2000;3(2):125-150.

Keligman. Nelson Textbook of Pediatrics, 18th ed. Philadelphia, PA: Saunders Elsevier. 2007.

Ramu A, Mehta MM, Leaseburg T, Aleksic A. The enhancement of riboflavin-mediated photo-oxidation of doxorubicin by histidine and urocanic acid. Cancer Chemother Pharmacol. 2001;47(4):338-346.

Zhao H, Yang X, Zhou R, Yang Y. Study on vitamin B1, vitamin B2 retention factors in vegetables.We Sheng Yan Jiu. 2008;37(1):92-96.

Vitamin A

Vitamin A is the name of a group of fat-soluble retinoids, including retinol, retinal, and retinyl esters [1-3].colorful-carrots

TWO FORMS OF VITAMIN A ARE AVAILABLE IN THE HUMAN DIET:
1.) Preformed Vitamin A (retinol and its esterified form, retinyl ester) – found in foods from animal sources, including dairy products, fish, and meat especially liver.

2.) Provitamin A Carotenoids [1-5] – found in plant foods such as sweet potato, spinach, carrots and canteloupe, etc.

The most important Provitamin A carotenoid is beta-carotene; other provitamin A carotenoids are alpha-carotene and beta-cryptoxanthin. The body converts these plant pigments into vitamin A.

Both provitamin A and preformed vitamin A must be metabolized intracellularly to retinal and retinoic acid, the active forms of vitamin A, to support the vitamin’s important biological functions [2,3]. Other carotenoids found in food, such as lycopene, lutein, and zeaxanthin, are not converted into vitamin A.

Retinol and carotenoid levels are typically measured in plasma, and plasma retinol levels are useful for assessing Vitamin A deficiency. However, their value for assessing marginal vitamin A is limited because they do not decline until vitamin A levels in the liver are almost depleted [3]. Liver vitamin A reserves can be measured indirectly through the “relative dose-response test”, in which plasma retinol levels are measured beforeand after the administration of a small amount of vitamin A [5]. A plasma retinol level increase of at least 20% indicates an inadequate vitamin A level [3,5,6].

For clinical practice purposes, plasma retinol levels alone are sufficient for documenting significant deficiency.
Vitamin A is critical for vision as an essential component of rhodopsin, a protein that absorbs light in the retinal receptors, and because it supports the normal differentiation and functioning of the conjunctival membranes and cornea [2-4]. It also supports cell growth playing a critical role in the normal formation and maintenance of the heart, lungs, kidneys, and other organs [2].

FOOD SOURCES

Sources of Retinoids: beef, liver, eggs, shrimp, fish, fortified milk, cheddar cheese and, Swiss cheese

Sources of Beta Carotene: sweet potatoes, carrots, pumpkins, squash, spinach, mangoes and, turnip greens

BEST AS SUPPLEMENT

Retinyl pamitate (fat soluble): it’s important to get adequate levels of vitamin A from retinyl palmitate because it plays a vital role in many functions in the body including vision, reproduction, bone growth, blood cell generation, and brain development.

Beta carotene (water soluble): whatever your body doesn’t need is passed in your urine, which means you can’t build up toxic levels, but you can end up with some very bright yellow urine. Since carotenoids can be converted into a different form of vitamin A (retinol) when necessary, it’s a good idea to give your body enough of them to use when it needs it.

INTERACTIONS WITH MEDICATIONS

Vitamin A can interact with certain medications, and some medications can have an adverse effect on vitamin A levels. Individuals taking these and other medications on a regular basis should discuss their vitamin A status with their health care providers.

Orlistat (Alli, Xenical), a weight-loss treatment, can decrease the absorption of vitamin A, other fat-soluble vitamins, and beta-carotene, causing low plasma levels in some patients [39]. The manufacturers of Alli and Xenical recommend encouraging patients on orlistat to take a multivitamin supplement containing vitamin A and beta-carotene, as well as other fat-soluble vitamins [40,41].

Retinoids such as psoriasis treatment acitretin (Soriatane) and bexarotene (Targretin), used to treat the skin effects of T-cell lymphoma. Retinoids can increase the risk of hypervitaminosis A when taken in combination with vitamin A supplements [39].

Vitamin B1

Thiamin is one of the water-soluble B vitamins. It is also known as vitamin B1.

sunflowerseedThiamin is naturally present in some foods. It is added to some food products, and available as a dietary supplement as thiamin mononitrate and thiamin hydrochloride (HCL). This vitamin plays a critical role in energy metabolism and, therefore, in the growth, development, and function of cells [1].

Ingested thiamin from food and dietary supplements is absorbed by the small intestine through active transport at nutritional doses and by passive diffusion at pharmacologic doses [1]. Most dietary thiamin is in phosphorylated forms, and intestinal phosphatases hydrolyze them to free thiamin before the vitamin is absorbed (thiamin pyrophosphate) [1]. The remaining dietary thiamin is in free (absorbable) form [1,2].

Humans store thiamin primarily in the liver, but in very small amounts [3]. The vitamin has a short half-life, so people require a continuous supply of it from their diet.

About 80% of the approximately 25–30 mg of thiamin in the adult human body is in the form of thiamin diphosphate (TDP; also known as thiamin pyrophosphate), the main metabolically active form of thiamin. Bacteria in the large intestine also synthesize free thiamin and TDP [4]. TDP serves as an essential cofactor for five enzymes involved in glucose, amino acid, and lipid metabolism [1,3].

FOOD SOURCES

Most nutritious foods contain some thiamin but these contain highest amounts: sunflower seeds, pork chops, ham, soymilk, watermelons, and acorn squash.

BEST AS SUPPLEMENT

Thiamin hydrochloride (HCL): it’s stable and water soluble [1,11] and available in many multivitamin/multimineral supplements with about 1.5 mg thiamin and sometimes more [11]. Supplements containing B-complex vitamins (including thiamin) or thiamin only are also available.

INTERACTIONS WITH MEDICATIONS

Although thiamin is not known to interact with any medications, certain medications can have an adverse effect on thiamin levels. Individuals taking these and other medications on a regular basis should discuss their thiamin status with their health care providers.

Furosemide (Lasix) is a loop diuretic used to treat edema and hypertension by increasing urinary output. Research has linked the use of furosemide to decreases in thiamin concentrations, possibly to deficient levels, as a result of urinary thiamin loss [48,57,58]. Whether thiamin supplements are effective for preventing thiamin deficiency in patients taking loop diuretics needs to be determined in clinical studies.

Fluorouracil (also known as 5-fluorouracil; Adrucil) is a chemotherapy drug that is commonly used to treat colorectal and other solid cancers. The published literature includes several cases of beriberi or Wernicke’s encephalopathy resulting from treatment with this drug, possibly because the drug might increase thiamin metabolism and block the formation of TDP, the active form of thiamin [59-62]. Thiamin supplements might reverse some of these effects.