Unfortunately, popping a vitamin won't speed up your metabolism. While niacin -- like the other B vitamins -- helps your body metabolize food into energy, it has no control over how many calories your body burns. Speeding up your metabolism requires a little more work from you: namely, you need to be more active physically. If you feel your metabolism is sluggish or you're struggling with your weight, consult your doctor to rule out any potentially underlying medical causes.
Niacin and Metabolism
The mistaken belief that niacin, which is also called vitamin B-3, boosts calorie-burning may stem from to the role it plays in carbohydrate and fat metabolism. Niacin helps metabolize carbohydrates into glucose, which your cells use for energy, but the vitamin has no control over how your body uses that energy. If you consume more calories than your body needs, the excess gets converted to fat and stored for later use, and this fat storage occurs even if there's extra niacin in your body.
Niacin also plays a role in lipid metabolism by decreasing the production of triglycerides and cholesterol in the liver, which is related to heart health, not calorie-burning and weight loss.
Your metabolism is like the engine that powers a car. Through a series of chemical reactions, your metabolism transforms the calories and nutrients from food into the energy your body needs to run smoothly. A large chunk of that energy -- called the basal metabolic rate, or BMR -- is used to breathe, repair cells, maintain muscle mass and keep your heart beating. The metabolism also supplies the energy used to digest and absorb food, known as the thermic effect of food. Calories burned via daily activity, including taking a shower, walking your dog and going on a weekend hike, are also part of your metabolism. Each person's metabolism is determined by genetics, gender, body size, body composition and how active you are throughout the day.
Getting Enough Niacin
Niacin deficiency is extremely rare in the United States, according to the University of Colorado Extension, with alcoholism as the primary cause. If an actual niacin deficiency occurs, it's usually due to significant calorie or protein restriction, such as what occurs during starvation. In severe cases, lack of niacin leads to a condition called pellagra, which is characterized by cracked skin, diarrhea and dementia.
A low intake of niacin may occur from eating a diet full of refined carbohydrates or too little protein, and it may cause health problems that have very little to do with your metabolism. These health problems may include fatigue, indigestion, canker sores and depression. It's easy to get enough niacin from foods such as peanuts, sunflower seeds, beets, whole grains, chicken, salmon and tuna.
How to Speed Up Your Metabolism
If you want to speed up your metabolism, you need to be more active, so adding cardiovascular exercise can help you, because it's most effective at burning calories. A 155-pound person burns 260 calories in a 30-minute, high-impact aerobics class and 355 calories for 30 minutes on the elliptical machine. But don't limit yourself to planned exercise. Boost your metabolism by fitting more activity into your day and usual routine. Work in your garden, coach your kid's baseball team, write emails standing up, pace when you're on the telephone and always take the stairs.
Because muscle burns more calories than fat, doing some strength training to build muscle may give your metabolism a little boost. On top of that, you'll burn 90 to 130 calories during each 30-minute weight-lifting session.