If you have a well-curated skin care regimen, chances are you've seen vitamin B3 on the ingredient list. But what exactly is it? And, more importantly, what does B3 do for your skin?

Vitamin B3, which is also known as niacinamide, has multiple benefits for the skin and should be on your radar for the long-term. We asked board-certified Dermatologist David Bank to break down what it is and how to use B3 for your skin.

What Is Vitamin B3?

Dr. Bank explains that vitamin B3 is a water-soluble vitamin that comes in two forms—niacin and niacinamide—and plays an important role in the functions of the skin and digestive and nervous systems.

The National Institutes of Health states that niacin helps turn the foods we eat into the energy we need and supports the proper development and function of our bodies' cells. According to the Mayo Clinic, our bodies produce niacin naturally, but it can also be found in foods like milk, meat, and cereal grains.

What Does B3 Do for Your Skin?

According to Dr. Bank, niacinamide applied topically can reduce the appearance of pores and redness, fortify the skin barrier, and smooth out wrinkles. These notions are supported by scientific studies, as are the claims that it can act as an antioxidant and can reduce the yellowing and hyperpigmentation that can come with aging.

It also is a powerful ingredient in treating acne, Dr. Bank explains. Niacinamide can decrease oil production, reduce red bumps with its anti-inflammatory properties, and help treat post-inflammatory discoloration.

The best part is that vitamin B3 is safe enough to use on even the most sensitive skin and can be used together with any ingredient. Dr. Bank suggests using a sunscreen that includes this multipurpose vitamin like EltaMD UV Clear Broad-Spectrum SPF 46 as part of your daily regimen for best results. Whatever sunscreen you pick, it should offer broad-spectrum protection and an SPF of 30 or more, applied to any skin that could be exposed to ultraviolet rays.

Should You Take an Oral Vitamin B Supplement?

Although its common to find B3 advertised on the packaging of topical products, there are benefits to the oral ingestion of this vitamin, as well.

As Bank explains, this nutrient has been observed to help prevent skin cancer when taken orally. In a New England Journal of Medicine study where researchers gave patients oral niacinamide or a placebo twice daily for 12 whole months, they found that there were 23 percent fewer cases of skin cancer in the group that received niacinamide orally than those who were given a placebo.

Dr. Bank also says that studies have shown that taking vitamin B3 orally might reduce inflammation seen with acne and rosacea while topical niacinamide has been shown to help with skin barrier repair and melasma.

According to the Mayo Clinic, oral vitamin B3 is sometimes prescribed for niacin deficiency and even as part of treatment for high cholesterol. Although it is generally safe, there can be side effects including skin flushing, itching, and nausea. Given that most people get their right amount of internal B3 from their body and diet, make sure to talk with your doctor before you start taking it for any of these reasons.

Supporting Your Skin with B3

With all that in mind, you can consider this key nutrient a must-have in your skin care routine. For B3 use beyond the skin barrier, always consult your general physician or Dermatologist for a professional opinion—keeping yourself, your doctors, and your regimen in sync is the surest way to keep that healthy glow going.