Not all cholesterol is bad. High-density lipoprotein, or HDL, is considered “good” cholesterol.
Higher levels of HDL are associated with lower risks of heart disease and stroke.
Certain foods, like those high in fiber, can help boost your HDL numbers.
Niacin, a B vitamin, has been shown to help increase HDL and lower both the “bad” LDL cholesterol in your blood and triglyceride levels.
In this article, I’ll talk more about what niacin is and its impact on cholesterol, as well as other benefits and risks from supplementing niacin.
I’ll also outline when you should talk to your doctor about niacin and your cholesterol levels.
What is Niacin?
Niacin (also known as vitamin B3) is a water-soluble molecule that is essential for the function of many different enzymes in the body.
It is also known as nicotinic acid or nicotinamide.
Niacin is naturally found in many foods and is sometimes added to food products.
It is also sold as a dietary supplement, both on its own and as part of multivitamins.
Most types of tissue in the body absorb the active forms of niacin: nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP).
NAD is essential for more than 400 different enzyme processes in your body.
The most notable of these processes is the conversion of the carbohydrates, fats, and proteins that you eat into adenosine triphosphate (ATP), the form of energy that your cells can use.
Without enough niacin, your body’s ability to process energy can be reduced.
NAD is also vital for:
- Producing enzymes that help cells function normally
- Maintaining genome integrity
- Controlling genetic expression (epigenetics)
- Cellular communication
NADP is required for synthesizing cholesterol and fatty acids and for supporting antioxidant functions in the cells.
Niacin is converted into active forms after it is consumed and then absorbed via the stomach and small intestine.
Since niacin is a water-soluble vitamin, it does not get stored in fat cells, but can be taken into red blood cells for a niacin reserve.
Excess niacin is excreted via the kidneys.
So when niacin intakes are high, it may be present in urine.
Niacin is not effectively tested via the blood. But the levels in your urine can be tested to determine if you’re taking in enough niacin.
Foods High in Niacin
Many foods contain niacin.
Tryptophan from foods may also be converted into niacin and is considered to be a dietary source of vitamin B3.
Foods that contain higher levels of niacin include:
- Brown rice
- Fortified breakfast cereals
What Impact Does Niacin Have on Cholesterol?
- If your HDL cholesterol is too low, niacin may help to increase it.
- If your LDL cholesterol is too high, niacin may help to decrease it.
- Niacin can also help decrease triglycerides.
Niacin is able to reduce cholesterol because it drops the number of fatty acids being activated from tissue storage and decreases how much LDL is synthesized.
It increases HDL by preventing the removal of it by liver cells, allowing the body to retain more.
While these are impressive benefits, niacin does not erase all risk for cardiovascular disease, even if it helps to normalize lipid levels.
This is because even as it helps to balance lipids, it may increase insulin resistance and contribute to potential blood glucose imbalance.
Who May Benefit From Taking Niacin?
Niacin used to be a common addition recommended to patients who were already taking cholesterol medication.
However, more recent research has found that niacin supplementation is not particularly beneficial if someone is already taking statins.
Niacin is not a first-line treatment for cholesterol, but is now reserved as an option for people who are unable to take statins or have had poor reactions to them.
Niacin may also benefit people who generally wish to support cardiovascular health, cognitive health, or who have known niacin deficiency.
Because niacin is vital for cellular energy processes, some doctors use NADH paired with other antioxidants to help address fatigue in chronic conditions.
How to take niacin
Niacin is typically taken once or twice per day.
Niacin doses are measured in mg NE, which stands for niacin equivalents.
The recommended daily intake for niacin varies based on age:
- Males 14 and older: 16 mg NE
- Females 14 and older: 14 mg NE
- Pregnant females: 18 mg NE
- Lactating females: 17 mg NE
The tolerable upper limit for all adults is 35 mg NE.
If you are taking niacin to support balanced cholesterol levels, the dosage may be higher. Niacin is available as a prescription, which allows for a verified way to regulate dose.
Supplemental niacin is also available, but the FDA does not regulate supplements in the same way that pharmaceuticals are managed.
Dosages can vary, and taking higher doses of dietary supplements could result in accidental overdose.
Side Effects of Niacin
The primary side effect of niacin is known as the “niacin flush.”
Taking more than your body is prepared to metabolize can result in reddened skin that looks hot and flushed.
It may also cause itching.
- High blood sugar levels
- Gastrointestinal upset
- Liver damage, increased liver enzymes, and liver failure
- Blurred vision
- Excessive sweating
- Low blood pressure
- Liver problems
- Peptic ulcer disease
- Inflammatory bowel disease
- Migraine headaches
Risks of Taking Niacin
Taking too much niacin for too long may increase the risk of metabolic syndrome or type 2 diabetes.
This happens because when niacin is present in higher amounts in tissues, it can prevent insulin from suppressing glucose synthesis in the liver.
This leads to higher circulating levels of glucose, causing elevated blood sugar.
Taking too much niacin, well over the tolerable upper limit, can result in a severe niacin flush that could also lead to organ failure.
Niacin interacts with some medications:
- Medications to treat type 2 diabetes (Metformin, others)
- Statins and other medications designed to lower cholesterol
- Thyroid replacement hormones
Some medications may decrease niacin levels:
- Isoniazid and pyrazinamide (Rifater)
There are other possible interactions.
Taking niacin with alcohol can increase the risk of flushing and liver toxicity.
When to See a Doctor
If you are interested in using niacin to decrease cholesterol levels, speak to your health care provider.
They will be able to help you determine whether niacin or a different lipid-lowering approach will work for you.
You should also speak with your provider if you are taking niacin and experiencing adverse side effects.
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K Health articles are all written and reviewed by MDs, PhDs, NPs, or PharmDs and are for informational purposes only. This information does not constitute and should not be relied on for professional medical advice. Always talk to your doctor about the risks and benefits of any treatment.
K Health has strict sourcing guidelines and relies on peer-reviewed studies, academic research institutions, and medical associations. We avoid using tertiary references.
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