As we all know vitamins form an essential part of our diet.
But why are they so important?
It is because these compounds are required at every step of the biochemical processes taking place in our body.
They are synthesized by our body in sufficient amounts and hence are to be obtained from diet. Deficiency of certain vitamins can manifest into diseases and cause damage.
There are 13 vitamins that are required by the body. They are categorized as:
- Fat soluble vitamins: They are stored in the fat tissue of the body. Vitamin A, D, E and K belong to this group.
- Water soluble vitamins: The other 9 vitamins fall in this category. They are utilised immediately and not stored.
Anyways coming to weight loss, haven’t we all wished for a magic pill that we could pop and lose weight in a few months!?
But is that actually possible? Well some believe this concept and consume vitamin supplements for weight loss.
Vitamin supplements do not aid a person who is otherwise healthy.
Having said this, we do not refute the idea that obese individuals should not consume vitamins.
Vitamins play a significant role in energy metabolism and fat deposition. Also individuals attempting to lose weight develop a deficiency of certain vitamins.
This article aims to go over the role of vitamins in energy and fat metabolism and their prospective effects on weight.
Scientific evidence regarding the role of vitamins in weight loss
The following studies reflect the relevance of vitamins in fat and energy metabolism at a molecular level and thus explain their role in weight loss.
Vitamin status in obese individuals
Obesity affects many parameters that are normal in healthy individuals. Altered vitamin status is one such parameter.
Metabolic syndrome is a group of conditions related to cardiovascular risk factors and obesity.
A research was conducted to observe the vitamin status of individuals suffering from metabolic syndrome in comparison to healthy individuals.
Vitamin A, C and E levels were significantly lower in subjects when compared to healthy individuals.
It was concluded that decrease in these levels contribute to the weak antioxidative capacity in patients suffering from metabolic syndrome.
In a study organized on prevalence of obesity and link between concentrations of different vitamins and features observed in obesity, a deficiency of Vitamin C and E was found in obese individuals.
Further it was observed that concentrations of Vitamin A and C were associated with BMI, body fat and hormones that regulate fat deposition.
According to the study, Vitamin A, C and E play an important role in fat metabolism.
Another study focussed on vitamin status in obese individuals reported lower concentrations of vitamin B6, C, D, and E than those found in healthy individuals.
Levels of Vitamin A, B1, B2, B12 and folic acid were found to be adequate in most obese individuals.
A review study reports that vitamins when consumed in excess can lead to weight gain.
Presence of food supplements in the market and the marketing hype associated with them has lead to increased consumption of vitamins.
B complex vitamins when taken at high doses lead to weight gain.
Formula feeds fortified with vitamins lead to weight gain in infants thus increasing risk of childhood obesity.
Increased vitamin intake is also correlated to prevalence of diabetes.
Just as the above study suggests that excess vitamin consumption is linked with obesity, this study suggests that a diet deficient in multivitamins can lead to weight gain.
In this study mice were fed a standard diet or a diet that met only 50% of daily vitamin requirement.
At the end of the study, it was found that body weight of mice in experimental group was 6% higher than that those in control group.
Also fat deposition was 2 folds higher in experimental group than in control group. These results indicate that there could be a possible role of vitamin deficiency in obesity.
What does this mean? Altered vitamin status could be a result of or even contributing to obesity.
Role of Vitamin A in Fat deposition
Vitamin A consists of retinol, retinal, retinoic acid and caretinoids.
Their prime function is to support a healthy immune system and good vision.
Cod liver oil, carrot, sweet potato, broccoli are good sources of Vitamin A.
The role of vitamin A in fat and energy metabolism is well documented.
Vitamin A and its related compound retinoic acid are stored in fat cells. Different forms of vitamin A are actively involved in fat metabolism and storage at molecular levels.
These mechanisms are now being linked with health issues such as diabetes and obesity.
Different components of regular diet can influence fat formation.
A study was organized to evaluate the relationship between vitamin A intake and adiposity (fat deposition) related parameters.
It was found that vitamin A is inversely related to adiposity that is higher consumption of vitamin A lower the risk of fat deposition.
Vitamin A consumption is directly associated with antioxidant intake and cholesterol levels.
Results of an experimental study conducted on obese mice indicate that doses of 52 and 129 mg/kg of vitamin A in diet can help reduce weight and prevent adiposity (fat deposition).
This effect is caused due to action of Vitamin A at a cellular level preventing deposition of fat.
The dose of vitamin A is of importance because the same group of researchers have proven that a dose of 129mg of Vitamin A/kg of diet can cause weight gain in obese mice.
This suggests that the effect of Vitamin A on weight gain or loss id dose dependant.
A research study proves that retinoic acid suppresses obesity. Retinoic acid is found to protect mice from diet induced obesity by two mechanisms:
- Preventing adipogenesis (formation of new fat cells)
- Promoting energy expenditure (burning of calories)
Retinoic acid regulates genes that enhance oxidation of fats and promote dissipation of energy. These mechanisms suggest that retinoic acid hold the potential of curbing obesity.
What does this mean? Apart from being responsible for healthy vision, vitamin A plays an important role in fat metabolism and energy regulation. This could be of relevance in treating obesity.
Role of Vitamin B complex in obesity
A group of 8 compounds together form vitamin B complex. They aid in activity of various enzymes. Legumes, bananas, potatoes and meat are good sources of vitamin B.
Micronutrient status can be an important contributing to childhood obesity.
In a study designed to evaluate the relation between concentration of vitamin B12 and body fat, it was found that high concentrations of vitamin B12 corresponded to lower BMI, low total body fat and low trunk fat.
High concentrations of Vitamin B12 were linked with reduced risk of obesity. Thiamine and riboflavin intake were found to inversely associated with BMI and trunk fat mass.
Ketogenic diet is a famous weight loss intervention.
It consists of a diet low on carbohydrates but high in fats. Research experiments were conducted to investigate the effect of ketogenic diet on biotin status.
Biotin is part of B complex vitamins and is commonly used to promote hair growth.
It was found that ketogenic diet increases biotin intake, makes biotin more available for utilisation and thereby promoting energy expenditure leading to weight loss.
It was concluded that individuals opting for ketogenic diet need biotin supplementation.
Hypothalamus is the part of the brain that control appetite and gut and fat cell responses. Damage to this portion can lead to excessive eating leading to obesity.
An experimental study was conducted to evaluate the effect of administering pantothenic acid derivatives in mice suffering from hypothalamic obesity. Pantothenic acid is also known as vitamin B5 .
The tested compounds were found to inhibit weight gain.
They reduced food intake and influenced blood glucose, insulin and cholesterol levels positively. The vitamins raised the activity of enzyme ‘lipoprotein lipase’ which facilitates breakdown of fats.
This demonstrates the role of pantothenic acid in controlling obesity.
Scientific evidence regarding altered vitamin B6 status in women following a low calorie diet is available. In this study subjects were asked to follow a diet with increased consumption of vegetables or cereals.
Weight reduction and increase in pyridoxine intake was observed in both groups.
However it was found that a diet rich in cereals can help improve vitamin B6 status and this can help maintain fat free mass during weight loss periods.
Homocysteine is a biologically vital chemical compound which requires vitamin B for functioning.
An imbalance in homocysteine levels is observed in obese or overweight individuals attempting to lose weight, however data is inconsistent.
Increased homocysteine levels can increase risk of cardiovascular levels.
In this study the subjects were given folate, vitamin B6 and vitamin B12 supplements in addition to restricted calorie intake. Along with weight reduction, improvement in homocysteine levels was observed.
Researchers concluded that oral vitamin supplementation can protect against elevated homocysteine levels occurring during weight loss.
What does this mean? B complex vitamins do not play a direct role in fat deposition. However certain consequences such as a diet lacking nutrients or altered vitamin status while losing weight can make consumption of vitamin B necessary.
Role of vitamin C in obesity
Vitamin C or L-ascorbic acid supports enzymatic action and serves as an antioxidant. Camu camu, Indian gooseberry, oranges and liver of various animals contain high levels of vitamin C.
Few of the mechanisms by which vitamin C could possibly act against obesity are:
- Regulate breakdown of fats in fat cells
- Inhibit glucose metabolism and secretion of leptin(hormone that favors fat deposition) in fat cells
- Reduce inflammation
- Improve glucose parameters in obese, diabetic patients
A study was designed with the objective to find a correlation between vitamin C and adiposity.
It was found that vitamin C levels were inversely related to BMI, body fat percentage and waist circumference. Also it was seen that vitamin C levels influenced the levels of adiponectin.
Further when the subjects were given a low calorie diet and Vitamin C supplements, a decrease in body weight was observed with increased levels of adiponectin.
Citrus fruits are a great source of Vitamin C.
A survey was conducted to evaluate how helpful is consumption of 100% orange juice in improving diet quality.
Orange juice consumers were 21% less likely to develop obesity than non consumers.
Compared to non consumers, consumers were found to have better profile of vitamins and nutrients including Vitamin C. Consumers had higher intake of fruits, grains and fruits juices.
They also had lower BMI and cholesterol levels.
Ascorbic acid is an active component of vitamin C. It is proven that ascorbic acid can inhibit development of adipocytes.
Ascorbic acid also affects genes involved adipogenesis and can reverse fat accumulation.
This activity of ascorbic acid at cellular level can be of use in obesity treatment.
Vitamin C status is found to influence fat oxidation during exercise.
Results of a clinical trial demonstrated that individuals with low vitamin C status oxidized 25% less fat per kg of body weight through exercise in comparison to those who had adequate vitamin C status.
Also supplementation with Vitamin C was found to raise the rate of burning of fats by 4 folds as compared to the rate seen in those having low vitamin C levels.
Interesting enough, vitamin C is found to inhibit the effect of anorectic drugs.
Vitamin C modulates ascorbic acid levels in the brain which influences the anti-obesity and anorectic activity of drugs such as fenfluramine.
In other words at certain doses ascorbic acid can improve appetite and lead to weight gain.
What does this mean? Vitamin C and ascorbic acid directly influence fat metabolism and appetite. However their effect is dose dependant.
Role of Vitamin D in obesity
Vitamin D mainly facilitates absorption of nutrients from the intestine. It is good for bone health. It can be either obtained from diet or from sunlight.
Vitamin D deficiency is linked with obesity. In a clinical trial aimed in observing whether vitamin D supplementation can improve weight loss outcomes
Subjects were asked to follow a weight loss regime and some were given Vitamin D supplements.
Weight loss occurred in both groups and the outcome was similar. Vitamin D supplementation was not found to have any effect on weight loss.
A similar study as above was conducted in which subjects were given Vitamin D and lactose as a placebo (similar but fake treatment).
No significant changes in body weight and waist circumference were seen in both groups. However a significant decrease in body fat mass was observed in vitamin D group.
A clinical trial reported the effect of calcium and vitamin D supplementation on obesity. The combination did not have a significant effect on body weight.
However a decrease in total fat mass and loss of fat from the stomach region was observed with supplementation of calcium and vitamin D.
Another study focussed on supplementing Vitamin D in response to deficiency and observing weight loss outcome reported that vitamin D supplementation can facilitate weight loss upto 5% of initial body weight.
In addition vitamin D supplementation has a positive effect on inflammation.
What does this mean? Numerous studies support the idea that vitamin D supplementation can enhance weight loss outcomes.
Role of other vitamins in fat metabolism
Vitamins in combination with other micronutrients do regulate energy and fat metabolism.
Magnesium improves the effect of Vitamin E in reducing fat content in obese rats.
Coenzyme Q is found to inhibit weight gain in obese rats by preventing synthesis of fats, promoting breakdown of fats and influencing genes involved in fat metabolism.
Poor vitamin K status is associated with increased adiposity and fat tissue is found to have high concentrations of vitamin K.
Scientific evidences help us understand that vitamins are essential not only for various biochemical processes occurring in the body but they also play important roles in energy expenditure, metabolism and fat deposition.
Deficiency of vitamins could be a result of obesity.
A number of weight loss supplements are available that are fortified with vitamins but evidence of their impact on weight loss is not consistent.
It would be wise to consume vitamin supplements only when diagnosed with a deficiency.
Nonetheless consuming fruits, vegetables and other natural sources can provide you with vitamins and they also contain components like fibre and proteins which aid in weight loss.