Does Vitamin C Play a Role in Fat Loss?


Some people think of vitamin C as a vitamin that protects against colds. No doubt, vitamin C, also known as ascorbic acid, plays a key role in keeping your immune system healthy but it’s health benefits go far beyond this. For example, vitamin C is a powerful antioxidant vitamin that helps regenerate other antioxidant vitamins, like vitamin E.

Not only is vitamin C powerful in the antioxidant department, you need it to build collagen, the tough, fibrous material that gives your skin and joints support and resiliency. Not getting enough vitamin C can have serious consequences. At one time, sailors died from the vitamin C deficiency disease scurvy because they didn’t have access to vitamin C-rich fruits and vegetables during their long ocean journeys. If you’re deficient in vitamin C, you might experience:

.   Swollen, bleeding gums

.   Poor healing of wounds

.   Increased risk of infection

.   Nosebleeds

.   Easy bruising

.   Fatigue

Remarkably, primates, including humans, and guinea pigs are the only two animal breeds that can’t make vitamin C and have to get it through diet.

Interestingly, some studies suggest that vitamin C plays a role in fat loss, that people who don’t get enough vitamin C in their diet may have more problems losing body fat. Is there any truth to this idea?

Vitamin C and Fat Loss

One reason vitamin C could play a role in fat loss has to do with a molecule called carnitine. For fat oxidation to occur, fatty acids have to enter the mitochondria, the energy-generating organelle inside a cell. It’s enzymes inside the mitochondria that break down fat to ATP. Yet getting into the mitochondria isn’t always easy. Carnitine to the rescue.  It’s carnitine that transports fatty acids across the difficult to traverse membrane of the mitochondria. Without carnitine, fatty acids can’t get to where they need to be to be broken down into energy. That puts a damper on fat loss. Guess what your body needs to make carnitine? Yup, it needs vitamin C.

So, how much does vitamin C impact fat oxidation or fat burning? In a study published in the Journal Nutrition and Metabolism, researchers made an interesting observation – participants with low levels of vitamin C in their bloodstream burned 25% less fat when they walked for 60 minutes on a treadmill. When, as part of another study, they gave participants with low vitamin C a vitamin C supplement, it boosted their ability to burn fat.

What about weight loss in the absence of exercise? Although research is limited, a double-blind, placebo-controlled study showed that obese participants who supplemented with three grams of vitamin C daily lost more weight than those who took a placebo. Less encouragingly, another study, in 2014, didn’t show a link between dietary vitamin C consumption and BMI, although it did show an association between low vitamin C and a larger waist circumference in participants genetically predisposed to obesity.

Do You Need More Vitamin C?

Based on limited research, it seems that people who are deficient in vitamin C can, based on limited evidence, have more problems oxidizing fat during exercise. Plus, vitamin C MAY help obese people who have low vitamin C levels lose weight. The question is whether getting more dietary vitamin C beyond correcting a deficiency helps with fat loss and how much do you need.

There’s little doubt that vitamin C plays a role in fat oxidation since you need it to make the fatty acid transporter carnitine. That doesn’t necessarily mean adding lots of it to your diet, especially if you’re not deficient, will help you get leaner. On the other hand, some studies suggest that you may need more vitamin C if you exercise, especially if you do intense workouts. That’s because vitamin C is an antioxidant vitamin that helps repair cellular damage and reduce inflammation. Intense exercise creates a temporary pro-inflammatory state, although longer term exercise in moderation appears to reduce inflammation.

Vitamin C may help with exercise recovery as well. Yet, this too is controversial since flooding your body with antioxidants prior to a workout may suppress your body’s natural antioxidant defense system and keep it from being activated. This could interfere with some of the health benefits of exercise. Supporting this idea, one study showed that endurance runners who took vitamin C and E supplements (both antioxidant vitamins) didn’t experience the expected mitochondrial adaptations to endurance exercise. It’s these healthy adaptations that give runners greater endurance. So, at least for longer distance runners, taking vitamin C or vitamin E in supplement form might be counterproductive. Yet keep in mind these were supplements, not vitamin C from dietary sources.

So is vitamin C helpful or a hindrance? A few studies show that vitamin C enhances muscle recovery and may reduce muscle soreness after a workout. Vitamin C is also vital for immune health. One study showed that ultramarathon runners who supplemented with 600 milligrams of vitamin C experienced fewer colds after a race. Of course, an ultramarathon is an extreme form of exercise.

Best Sources of Vitamin C

If you need more vitamin C in your diet, where should you get it? As you probably know, fruits and vegetables are the best bets for upping your vitamin C intake. When you think vitamin C, think citrus fruits, but also consider berries, papaya, watermelon, pears, kiwifruit, red peppers, green peppers, melons, and bananas.

Women need around 75 milligrams a day and men 90 milligrams of vitamin C daily. One of the very best sources of vitamin C is guava. A half cup has 188 milligrams, enough to meet your body’s requirement for two days. Munching out on two pieces of fruit daily along with a varied whole food diet and you should get more than the amount your body needs to stay healthy, even if you exercise.

The Bottom Line

Whether not getting enough vitamin C hinders fat loss still isn’t clear. It wouldn’t be surprising if it played some role since you need vitamin C to make carnitine and carnitine to oxidize fat. Based on what we know the best approach is to consume enough foods high in vitamin C by adding whole fruit to your diet. Avoid vitamin C and E supplements, especially around the time of a workout as there’s some evidence that they interfere with positive workout adaptations.

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