Vitamin B Complex and Weight Gain

There are, in total, ​eight varieties of vitamin B​ in the B vitamin group. Your body ordinarily receives its daily required amount from foods such as meat, fish and dairy. Vitamin B complex is the label for a vitamin supplement that contains more than one of these B vitamins or that includes all eight of them.

The eight that make up a vitamin B complex supplement each has individual benefits that are integral to many important bodily processes. But they may have an effect on weight gain, which is important to consider before increasing your daily intake.

​Read more:​ Are Vitamin B12 Pills Good for Weight Loss?

Thiamin, or vitamin B1, has the primary role of converting glucose into energy and plays a key role in maintaining the health of the nervous system.

It can be found in whole-grain cereals, and in seeds, legumes, yeast and pork.

Thiamin deficiency can endanger the workings of the nervous system and can even affect the cardiovascular and gastrointestinal systems if not treated properly.

​Role in weight gain:​ A March 2015 study published in the ​Journal of Advances in Nutrition​ found that there was a link between people with obesity and a thiamin deficiency, suggesting that thiamin deficiency may actually contribute to weight gain. The study did conclude that further trials would need to take place for a concrete conclusion, but, nonetheless, the link was present.

Riboflavin, also known as vitamin B2, is instrumental in ​skin health​ and improving vision. Also, like many vitamins in the B group, it aids in the production of energy.

Riboflavin can be found in milk, yogurt, whole-grain bread and leafy green vegetables.

Though it is rarer than other deficiencies, riboflavin deficiency can occur. Symptoms include dry, cracked mouth, inflammation of the tongue, sensitivity to light and redness in the eyes. This deficiency is usually associated with excessive alcohol intake.

​Role in weight gain:​ There is no clinical evidence to suggest riboflavin has any particular role in weight gain or loss, so among the vitamins included in a B complex supplement it is largely inconsequential where weight is concerned. It is, however, important in the metabolism of fats, so should still be part of your diet.

Niacin, or vitamin B3, plays an integral role in converting fat, carbohydrates and alcohol into energy. Similar to riboflavin and thiamin, it aids in promoting skin integrity and the health of the nervous system. It can be found in poultry, milk, eggs and mushrooms.

If you consume an excessive amount of niacin, however, it can result in side effects such as itching, hot flushing and, potentially, liver damage. When the body is deficient in niacin, symptoms include increased irritability, mental confusion, loss of appetite and dizziness.

​Role in weight gain:​ Niacin in higher doses can be used to combat high cholesterol and high blood fat, but there is no significant link between niacin intake and weight gain or weight loss. Deficiency can cause loss of appetite, but this does not mean that higher levels of niacin encourage weight gain.

Pantothenic acid, or vitamin B5, is beneficial in the body's production of red blood cells and steroid hormones.

It can be found in many foods, particularly in liver, kidneys, peanuts and legumes.

As with riboflavin deficiency, it is incredibly rare to be deficient in pantothenic acid because it is present in almost all foods, but symptoms include fatigue, vomiting and digestive issues.

​Role in weight gain:​ There is no clinical evidence to suggest pantothenic acid plays a significant role in weight gain or loss.

​Read more:​ Does Vitamin B Complex Help You Lose Weight?

Vitamin B6 influences brain processes and even aids in the brain's development, while also being beneficial for the immune system.

It can be found in fish, shellfish, fruit and nuts.

It's important to be wary of the amount of vitamin B6 you consume. Excessive amounts, particularly through supplementation, can result in nerve damage. Symptoms include difficulties in mobility and numbness of the hands and feet.

​Role in weight gain:​ The only clinical evidence suggesting a correlation between vitamin B6 and weight gain is from a 2008 study published in the ​International Journal of Obesity​, which found that higher levels of B6 correlated with a ​loss of weight in women with obesity​. However, this is not demonstrative of vitamin B6 being instrumental in weight loss.

Vitamin B12, also known as ​cyanocobalamin​, promotes the growth and health of red blood cells, mental agility and the ​breakdown of fatty acids​ to create energy.

Harvard Health Publishing advises that sources of vitamin B12 can be found in almost any food that is of animal origin, which is why those committed to a vegan or vegetarian diet need to keep an eye on their vitamin B12 intake to make sure they are getting enough.

Harvard Health Publishing also advises that symptoms of deficiency include fatigue, loss of appetite, shortness of breath and even mental problems such as depression and memory loss.

There is a link between ​vitamin B12 deficiency and weight​ ​gain​ because it plays an important role in the conversion of fats into energy.

When the body is deficient in vitamin B12, it will begin to convert particular nutrients into fat as opposed to energy. Therefore, by keeping the body topped up with the levels of vitamin B12 it requires, any excess nutrients will be converted into energy as opposed to excess fat.

Vitamin B intake can be supplemented through injections as well as with B complex capsules. ​B complex injections​ can also provide you with the additional B vitamin levels you may require.

Though there is no specific, proven link between B complex injections and weight gain, there are extraneous factors that may affect the body's overall weight when B complex injections are incorporated.

The Mayo Clinic explains that B complex injections aid in the ​acceleration of the breakdown of fats​ within the metabolic process, and B complex vitamins such as B12, riboflavin, niacin and thiamin all play an integral role. This acceleration of the process makes it so less fat is deposited in the body, which may prevent excessive weight gain.

​Read more:​ How Does Vitamin B Complex Help Your Body?