NIACIN
1. What is the nutrient?
The nutrient is niacin which is a water soluble type B vitamin. Niacin aids in the
digestive system, skin and nerve function as well as the conversion of food to energy for
the body from carbohydrates. Niacin can be reached solely through dietary sources.
Typically, people in third world countries have niacin deficiency and people in the US do
not; however, when they do it is usually caused by alcoholism. Niacin is mainly used for
high cholesterol, but it can also be used for acne, memory loss, arthritis and circulation
problems.
http://www.nlm.nih.gov/medlineplus/ency/article/002409.htm
2. What is the RDA/DRI for the nutrient?
Factors that affect the amount of niacin include age, gender, and pregnancy. The
Recommended Dietary Allowance (RDA) is the average daily intake that is enough to
meet the nutrient requirements of nearly all (97 - 98%) healthy people. The daily
recommended intakes are listed below in the chart.
http://iom.edu/Activities/Nutrition/SummaryDRIs/~/media/Files/Activity%20Files/Nutrit
ion/DRIs/RDA%20and%20AIs_Vitamin%20and%20Elements.pdf
3. How is the nutrient metabolized?
Niacin is well absorbed when taken by mouth due to being water-soluble.
When taken in a physiologic dose it is metabolized in the liver into
niacinamide, and when a therapeutic dose is taken only a portion is
converted. It is widely distributed throughout the body and eventually gets
excreted through the urine. People with liver problems need to be careful
when consuming high doses of niacin because this can cause even more
problems to arise.
Niacin is dose rate specific and one pathway is through a simple conjugation
step with glycine. Another pathway forms nicotinamide adenine
dinucleotide. It is further metabolized into other compounds and there is a
nonlinear relationship between niacin dose and plasma concentrations after
multiple dose administration.
http://www.rxmed.com
www.webmd.com
http://www.rxlist.com/niaspan-drug/clinical-pharmacology.htm
4. What are food sources of the nutrient?
Food sources of niacin include dairy products, eggs, enriched breads and cereals, fish,
lean meats, legumes, nuts and poultry. Specifically, beets, beef liver, sunflower seeds,
and peanuts are great sources.
Food
Serving
Niacin (mg)
Chicken (light meat)
3 ounces* (cooked without skin)
7.3-11.7
Tuna (light, canned, packed in
water)
3 ounces
8.6-11.3
Turkey (light meat)
3 ounces (cooked without skin)
Salmon (chinook)
3 ounces (cooked)
8.5
Beef (90% lean)
3 ounces (cooked)
4.4-5.8
Cereal (unfortified)
1 cup
5-7
Cereal (fortified)
1 cup
20-27
Peanuts
1 ounce (dry-roasted)
Pasta (enriched)
1 cup (cooked)
1.9-2.4
Lentils
1 cup (cooked)
2.1
Lima beans
1 cup (cooked)
0.8-1.8
Bread (whole-wheat)
1 slice
1.3
Coffee (brewed)
1 cup
0.5
10.0
3.8
http://lpi.oregonstate.edu/infocenter/vitamins/niacin/
http://umm.edu/health/medical/altmed/supplement/vitamin-b3-niacin
http://www.nlm.nih.gov/medlineplus/ency/article/002409.htm
5. What disease states alter the nutrients metabolism?
Niacin is affected by diseases states such as defective tryptophan absorption,
long term use of chemotherapeutic treatment, people with Hartnups disease,
increased serotonin levels, drugs given for Parkinson’s disease, people with
chronic alcoholism and with HIV.
http://lpi.oregonstate.edu/infocenter/vitamins/niacin/#deficiency_causes
6. What are the tests or procedures to assess the nutrient level in the
body?
A niacin skin flush test can be conducted as well as a urine test to assess
niacin metabolites in the urine.
7. What is the drug –nutrient interactions?
These are a list of some of the drug interactions as specified by the University of
Maryland Medical Center.
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.
Aspirin -- Taking aspirin before taking niacin may reduce flushing from niacin, but take
it only under your doctor's supervision.
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.
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These are a list of medications that may lower levels of niacin in the body:
Azathioprine (Imuran)
Chloramphenicol (Chloromycetin)
Cycloserine (Seromycin)
Fluorouracil
Levodopa and carbidopa
Mercaptopurine (Purinethol)
University of Maryland Medical.
Center http://umm.edu/health/medical/altmed/supplement/vitamin-b3niacin#ixzz2zk4w434C
8. How is the nutrient measured?
Niacin is measured by the urinary excretion of niacin metabolites. Urine is
tested to help tell niacin levels through niacin elimination.
http://lpi.oregonstate.edu/infocenter/vitamins/niacin/
9. What is the Upper Tolerable Limits?
This is based on skin flushing which is a common side effect of niacin.
http://www.nrv.gov.au/nutrients/niacin
10.What are the physical signs of deficiency?
Symptoms of deficiency include indigestion, fatigue, canker sores, vomiting,
depression, and if niacin deficiency because extremely bad then pellagra may occur.
Pellagra includes signs of scaly skin, and diarrhea. Other signs such as a swollen red
tongue may present.
http://umm.edu/health/medical/altmed/supplement/vitamin-b3-niacin
11.What are physical signs of toxicity?
Signs of niacin toxicity include severe skin flushing, rapid heart beat, itching, nausea and
vomiting, abdominal pain, diarrhea, and severe liver damage. More severely niacin
overdose can lead to hepatotoxicity. This occurs when doses above 500mg are taken
which is rare.
http://www.mayoclinic.org/diseases-conditions/high-blood-cholesterol/expertanswers/niacin-overdose/faq-20058075