Can Vitamin Deficiency Cause Weight Gain?


Many people around the globe have vitamin deficiencies for a variety of reasons. Unless severe, vitamin-related deficiencies often go clinically unnoticed. However, even the slightest insufficiency might lead to significant consequences on general health.

Vitamins are known as essential nutrients because they perform crucial roles in our body, ranging from promoting healthy growth and development to boosting our immune system to fend off infections.

Vitamin deficiency occurs when the body is not receiving enough vitamins, either due to poor dietary choices or a chronic medical condition. Depending on which essential vitamin is deficient, individuals may experience various detrimental effects on their health. One of the overlooked factors is that missing out on some recommended vitamins contributes to progressive weight gain.

What is vitamin deficiency?

Vitamin deficiency is a condition that occurs due to a prolonged lack of vitamins. It can happen when a person is not getting enough vitamins due to poor lifestyle choices (primary deficiency) or malabsorption due to any underlying health disorder (secondary deficiency). 

Our body requires all 13 essential vitamins acquired from our diets to function properly.

Following are the 13 essential vitamins that are needed for normal body function:

  • Vitamin A
  • Vitamin C
  • Vitamin D (also nicknamed the ‘sunshine vitamin’)
  • Vitamin E
  • Vitamin K
  • Vitamin B1 (thiamine)
  • Vitamin B2 (riboflavin)
  • Vitamin B3 (niacin)
  • Vitamin B6 (pyridoxine)
  • Vitamin B12 (cyanocobalamin)
  • Pantothenic acid (B5)
  • Biotin (B7)
  • Folate (folic acid or B9)

Vitamin deficiency can affect anyone, and it generally co-exists with mineral deficiencies (zinc, iron, calcium, iodine). Insufficient amounts of vitamins can result in serious complications. Children, aged adults, and pregnant and lactating individuals are more susceptible to developing vitamin deficiencies because of their increased nutritional needs. Fortunately, vitamin deficiencies can be corrected with the right course of management with vitamin supplements.

Signs and symptoms

The following are the most common symptoms of vitamin deficiency:

  • Fatigue
  • Low bone density
  • Muscles weakness or cramps
  • Mood swings
  • Rough hair
  • Dry or itchy skin 
  • Slow wound healing
  • Bleeding gums
  • Skin hyperpigmentation
  • Back pain
  • Recurring infections
  • Weight gain
  • Depression
  • Poor vision


Mostly, vitamin deficiency is related to dietary intake. Vitamins are the essential organic substances generally found in the healthy food options that we eat. Some of the foods are even fortified with different vitamins. For example, milk contains calcium, but in many regions, it is also fortified with vitamin D.

Medical issues: Medical illnesses can result in vitamin malabsorption, even if the vitamin intake is sufficient. Medical problems like malabsorption syndrome, chronic diarrhea, and inflammatory bowel disease (particularly Crohn's disease) can cause vitamin deficiencies.

Some autoimmune diseases like those observed in pernicious anemia, affect the vitamin B12 absorption in the small intestines, eventually resulting in anemia.

Restricted Diets: Some other contributing factors that can cause vitamin deficiency may include restricted diet plans. Any meat-free diet may increase the risk of developing vitamin B12 deficiency. Diets that are high in processed foods and low in vegetables and fruits may lead to vitamin E, K, and C deficiency and much more. 

In addition to this, a review indicated that adhering to a gluten-free diet can result in nutrient deficiencies, especially vitamin D, B12, and folate.1 Although many diets are considered an important treatment factor including gluten-free diets for celiac disease. Hence, it is best to communicate with your doctor first before adhering to any diet plan.

Scarce sunlight exposure: Sunlight is also an essential source of Vitamin D. People who tend to spend more time indoors or live in heavily polluted areas might become deficient in vitamin D. In northern countries, it is fairly common to observe vitamin D inadequacy during the winter season.

Common causes of weight gain

There are several common causes that contribute to retaining excessive weight. Being overweight adversely affects our body since it can put us at a higher risk of developing major complications such as cardiovascular problems, diabetes, osteoarthritis, certain cancers, and many more. Obesity is becoming more prevalent globally. In the UK, it is estimated that 1 in every 4 adults is affected by obesity.

The potential causes of obesity are:

  • Unhealthy diet: Consuming high-calorie food consisting of fast food, sugary items, and beverages with an unhealthy nutritional choice contributes significantly to weight gain
  • Sedentary lifestyle: People tend to gain weight easily if they eat more calories than they burn through daily routine activities
  • Certain diseases: Some health-related issues may also contribute to weight gain, such as Prader-Willi syndrome, Cushing's syndrome, and polycystic ovarian syndrome (PCOS)
  • Medications: Some certain medicines, like antidepressants, diabetes medicines, antipsychotics, steroids, beta-blockers, and anti-seizure medications, may also lead to obesity in some individuals
  • Emotional factors: Obesity can have a great dependence on emotional well-being. Especially since many individuals tend to consume high-calorie foods when they are emotionally distressed

Other causes include:

  • Age
  • Family inheritance
  • Pregnancy
  • Smoking
  • Poor sleep cycle
  • Changes in the gut microbiome (due to illnesses, stressors, medications, diet)

How does vitamin deficiency cause weight gain?

Vitamins assist the body to be in an optimal state to utilise energy. This involves several processes to handle the stimulation of appetite, weight control, and the breakdown of essential food components to facilitate energy and metabolism. However, when the body is deprived of these crucial nutrients, the normal mechanism is disrupted, eventually leading to unwanted weight gain. 

The following are some of the reasons which may result in obesity:

Food cravings: A lack of vitamins for some people might trigger the appetite center of the brain for uncontrollable cravings. For instance, low vitamin D levels activate the brain's appetite center to consume more, which is often dependent on excessive, high-calorie, and processed foods. Such uncontrollable cravings contribute to weight gain.2

Fatigue: Low vitamin intake causes tiredness, limiting physical activity. Furthermore, vitamin D deficiency is often related to fatigue and depression. In vitamin D deficiency, there's a decline in calcium adsorption (hypocalcemia), which eventually leads to overactivity of parathyroid glands to balance the normal blood calcium levels (hyperparathyroidism). This shuttle mechanism can cause fatigue, muscular cramps, and even depression, making it harder to perform daily activities, eventually leading to weight gain.

Slow metabolism: Missing out on essential vitamins from the diet can slow down the metabolism. This can adversely contribute to slow calorie burn and progressive weight gain.2


Vitamin deficiencies can cause several complications including:

  • Numbness in hands and feet 
  • Severe weakness
  • Vision loss
  • Decrease in cognitive abilities
  • Mood changes
  • Shortness of breath
  • Rapid heart palpitations
  • Troubled sleeping
  • Severe hair loss
  • Increased chances of stroke risk

Managing weight gain and vitamin deficiency

The most efficient way to manage weight gain and vitamin deficiency is to replenish your nutritional needs and adhere to positive lifestyle changes.

Dietary changes – To counter the nutritional deficiency, creating a healthy meal plan along with your dietitian is the ideal option to replenish your needs. Your doctor may also prescribe vitamin supplements to optimise your health.

Several studies have confirmed a relationship between excessive body fat and vitamin D deficiency. However, the nature of this association is still unclear.3 It is observed that supplementing with vitamin D and physical activity has a significant effect on weight loss and weight management.

Limit cravings – Adding multivitamins or adhering to a highly nutritious diet with daily physical exercise can assist in reducing unhealthy cravings.

Stress less – Stress is one of the major culprits of weight gain. Try meditation, yoga, a brisk walk, and a vitamin-rich diet to reduce cortisol levels and manage weight.

When to seek medical attention

The treatment of most deficiencies is fairly simple, and the best way to identify the causes is to communicate with your doctor regularly. A simple blood test can help to detect vitamin deficiencies.

If you find any of the symptoms persist or worsen, then it is advised to seek medical attention immediately:

  • Blurred vision
  • Distorted night vision
  • Irregular heartbeats
  • Severe bone pain
  • Memory loss
  • Reduced physical or cognitive abilities
  • Bleeding gums, or skin irritations


Vitamins are essential nutrients that perform thousands of roles to maintain bodily functions. Vitamin deficiencies occur when there's a long-term decline in the body's vitamin needs due to an unhealthy lifestyle or chronic medical problems. Vitamin deficiency can affect people of all ages. If ignored, vitamin deficiency can have gradual detrimental effects and may result in progressive weight gain. Fortunately, the treatment for reversing the condition is fairly simple. It is important to pay attention to receiving adequate amounts of nutrition to prevent vitamin deficiency. Communicating concerns with your doctor and adhering to a better lifestyle, involving in physical activity, and planning a healthy meal plan can all help to reduce weight gain and other more dangerous effects of vitamin deficiencies.


  1. Vici G, Belli L, Biondi M, Polzonetti V. Gluten free diet and nutrient deficiencies: A review. Clinical Nutrition. 2016 Dec;35(6):1236–41. Available from:
  2. Sheikholeslami-Vatani D, Rostamzadeh N. Changes in appetite-dependent hormones and body composition after 8 weeks of high-intensity interval training and vitamin d supplementation in sedentary overweight men. Front Nutr. 2022 Feb 7;9:827630. Available from:
  3. Vranić L, Mikolašević I, Milić S. Vitamin d deficiency: consequence or cause of obesity? Medicina. 2019 Aug 28;55(9):541. Available from:
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Sadaf Ahmed

Master of Science - MSc, Physiology, Clinical & Molecular Hematology, Karachi University, Pakistan

Sadaf is an experienced writer who creates a quality and well-researched scripts particularly related to Health Sciences.

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