Medically Reviewed

Looking to Gain Weight? Find Out Which 13 Vitamins and Supplements Might Help

Vitamins by themselves won’t help you gain weight. But when you use them as part of a weight-gaining strategy, they can support your goals.

Getting to a weight that is healthiest for you is an individual journey. Weight alone is not the most important measure of wellness, and many factors contribute to determining a healthy weight range. While weight loss gets much attention on the internet, everyone’s health needs are different. Some people need to gain weight to be at an optimal place for their well-being.

Nutritional support from vitamins and supplements may benefit overall health goals, including a healthy weight. But not all nutrients have the same impacts. Learn about 13 nutrients that may support your healthy weight goals.

Can you take vitamins to gain weight?

Vitamins are important micronutrients. They support health in countless ways. Most vitamins have recommended dietary allowances (RDAs) that apply to most of the population. Some are easy to get plenty of through your daily diet, while others are not commonly found in foods, like vitamin D.

Vitamins are essential for overall metabolic function, which have an impact on body weight. Micronutrient deficiencies can have profound effects on numerous aspects of your health, ranging from cellular and DNA function to digestion, immune system responses, hormone synthesis, nervous system function, musculoskeletal wellness, and much more. While vitamins are important for health, none have been shown to explicitly cause weight gain. However, when you want to support healthy body weight, it makes sense to ensure that your nutritional basics are met.

Most of your vitamins and minerals should come from foods, but dietary supplements can be beneficial to fill in gaps and help round out your daily nutrient needs. You can do this through multivitamin or prenatal supplements or by taking individual nutrients on their own.

Whatever you take, remember that any dietary supplement should be discussed with your medical provider first. Vitamins may be necessary for health, but in supplement form, there are other considerations, and only your medical provider can determine what, and how much, is optimal for your health.

Vitamins and supplements to help gain weight

There is not research that specifically links a vitamin with a specific amount of weight gain in a set timeframe. The importance of vitamins and supplements for weight gain comes from encouraging optimal physiological function and energy use.

1. Vitamin A

Vitamin A is the term for a group of fat-soluble retinoids. You need vitamin A for many things, including healthy immune response and cell division. Research in animals and in vitro have found an association between vitamin A and adipose tissue, which stores fat and converts vitamin A to the active metabolite form. The metabolitcs of vitamin A are important for gene regulation, affecting numerous metabolic processes. However, the current limited research primarily focuses on vitamin A and its role in weight loss or weight management, although other research does note that deficiency in vitamin A tends to be associated with poor nutritional status.

Vitamin A is an important nutrient. Healthy intake can be supported through many foods, including those that contain activated or preformed vitamin A (liver, butter, and other dairy products) as well as beta-carotene food sources like sweet potatoes, spinach, pumpkin, carrots, cantaloupe, and mango. You can also use dietary supplements to support vitamin A. Cod liver oil provides a source of preformed vitamin A, as do retinol supplements, although these should be avoided by pregnant people, or those who could be, since they can be teratogenic. Most dietary supplements like multivitamins contain vitamin A as beta-carotene which the body can then convert to vitamin A.

2. B Vitamins

B vitamins are a group of nutrients that work together to support the health of many important cellular, metabolic, neurological, circulatory, immunity, and DNA functions. The B-complex vitamins include:

  • Thiamin (vitamin B1)
  • Riboflavin (vitamin B2)
  • Niacin (vitamin B3)
  • Panthothenic acid (vitamin B5)
  • Pyridoxine (vitamin B6)
  • Folate or folic acid (vitamin B9)
  • Cobalamin (vitamin B12)

None of the B vitamins are known to cause weight gain. But they are needed for many enzymatic processes that happen at a cellular and DNA level, so deficiencies can impact how well your body functions. If you are looking to increase your muscle mass or gain weight in a healthy manner, supporting healthy intake of the B vitamins is important. Deficiency or inadequate intake could undermine your goals.

There are many foods that provide B vitamins, although B12 is primarily found in animal food sources, so vegan and vegetarian diets typically require supplementation. While B12 will not cause weight gain, deficiencies can lead to metabolic, hormonal, and neurological changes that can cause loss of appetite or energy conversion problems, which could impact how much you eat and how strong and active you are.

B vitamin supplements can be found on their own, in a B complex formula, or as part of a multivitamin or prenatal.

3. Vitamin C

Vitamin C is an antioxidant nutrient that most people think of as being tied to healthy immune function. But your body needs it for many things. As an antioxidant, it supports the body’s response to oxidative stress, which is a normal byproduct of cellular energy production. Research on vitamin C and weight focuses mostly on weight loss and metabolic wellness. However, vitamin C supports the absorption of iron, a mineral that is essential for healthy red blood cells. You need red blood cells for energy and nutrient transportation through the body, which is also needed for muscle development, growth, and overall health.

Vitamin C is found in many foods, primarily fruits and vegetables. It can also be obtained from multivitamins, prenatal vitamins, and standalone dietary supplements.

4. Vitamin D

Vitamin D does not cause weight changes on its own. The highest-quality evidence only links vitamin D directly to bone health, however other research has found associations with vitamin D and other health factors, including metabolic health and weight.

To support healthy body composition and muscular wellness, vitamin D’s impact on bones is what matters. Muscle weighs more than fat, so building muscle is a healthy strategy for healthy weight gain. Musculoskeletal health relies on vitamin D, particularly since some research has associated low vitamin D with weak muscles.

There are not a lot of foods that provide ample amounts of vitamin D. The primary sources of this fat-soluble vitamin come from the sun and from dietary supplements.

The impact of a vitamin D deficiency on weight gain

Vitamin D deficiency tends to be more common in those who have a higher body weight or more body fat. The primary effect on weight from most evidence seems to be supporting body weight with loss, not gain. Low vitamin D levels may be associated with fat, but not muscle, increases.

If you want to increase your body weight, reducing your vitamin D won’t lead to healthy weight gain, though, and could lead to other systemic complications. Vitamin D is an important nutrient for many body systems so it is important to ensure your levels are sufficient.

5. Fish oil and Omega-3 fatty acids

Fish oil is a common source of omega-3s, a type of polyunsaturated fatty acid that supports health in many ways. Fish oil and healthy omega-3 fats are not directly linked to weight gain, but they support numerous elements of structural and foundational well-being: circulatory, immune system, neurological, musculoskeletal, gastrointestinal, hormonal, skin, and cellular health.

Omega-3 fats have been a focus point for research that supports healthy weight loss. One of the mechanisms focuses on the gut microbiome and the immune system, and how these can affect health in a bunch of ways. Even though they are studied for healthy body composition that involves weight loss, similar mechanisms are important for overall body balance. If someone needs to support healthy body composition by gaining weight, the gut microbiome is still an essential site for digestion and nutrient absorption. Omega-3 fatty acids support healthy cellular communication, which is an important factor for muscle building, metabolic health, and overall body balance. Fish oil paired with protein, an important nutrient for muscle building, may also support healthy weight gain and body composition.

The body cannot make omega-3 fats, so they have to be obtained from dietary sources or fish oil supplements. Salmon and other coldwater fatty fish are excellent sources. Vegan omega-3 fish oils are also available, which are made from algae.

6. Iron

Iron is a mineral that is a vital component of hemoglobin, a red blood cell protein that carries oxygen to tissues in the body. Iron is also a key element of myoglobin, a different protein that is necessary for healthy muscles and connective tissues. An iron deficiency can slow physical growth or contribute to other strength, energy, and neurological challenges.

While some research shows that iron treatment can lead to weight gain, the context is not in a positive manner. When iron infusions increase ferritin, the storage form of iron, it can include weight gain and multiple other health complications. This is because ferritin is also used as a marker of how the immune system and overall body respond to acute or chronic challenges.

While healthy iron intake is necessary for energy, oxygen transport, and healthy muscles, excess iron can lead to disruptive processes in the body that can worsen, not support, body composition and strength goals.

Not everyone needs iron. Menstruating and pregnant people are most likely to need higher iron food intake or dietary supplements. The RDA for iron in adult persons born with male anatomy is just 8 mg. For adult persons born with female anatomy, it is 18 mg, and increases to 27 mg for pregnancy. This is directly related to blood, hemoglobin, and iron stores that are lost through regular menstruation, blood volume increases during pregnancy, and possible blood losses during birth. Because iron is not needed by many people, and the body stores minerals, do not start taking an iron supplement unless directed by your healthcare provider. Iron toxicity is a possibility and can cause serious complications.

Iron comes in two forms: heme (from animal-sourced foods) and nonheme (from plant-based foods). Some foods like meat, poultry, and seafood contain both forms of iron. The highest food source are fortified breakfast cereals, but other iron-containing foods include oysters, beans, liver, lentils, and spinach.

7. Protein

Protein is a macronutrient source of many vitamins and minerals. It also supplies amino acids, which are the building blocks of muscle and many other cellular and DNA components in the body. If you are looking to support healthy body composition and weight gain, protein is necessary.

Protein needs vary based on anatomy, activity level, age, and stage of life, as well as health goals. If you want to increase muscle, you will have higher protein needs. Daily protein recommendations are based on a person’s body weight. They are written as the number of grams of protein per kilogram of body weight (g/kg) each day. The general protein recommendation is 0.8 g/kg, but for moderate activity level and muscle building, the recommended range is 1.6–2.4 g/kg.

If you struggle to eat more protein, protein shakes can be beneficial to increase this macronutrient and support your healthy weight goals.

8. Creatine

Creatine is a combination of amino acids that is popularly used by athletes and high-level trainers. It supports how the body can draw from energy stores, muscular strength, and recovery after high-impact physical activity. On its own, creatine cannot support increased muscle mass or body composition changes. It only works as a supplement to boost energy and performance when combined with exercise. Adequate food intake, physical activity, and other aspects of a healthy lifestyle are still needed.

Creatine is naturally found in protein foods like seafood, poultry, red meat, and pork. When used for muscle building, it is typically taken in supplement form right before exercise or athletic events. Some people load creatine levels over a period of time while others take small doses over a certain timeframe. If you take a creatine supplement, don’t forget to hydrate. Creatine supplements can lead to water retention as a short term side effect especially if you do not increase your fluid intake to match your higher activity level.

Don’t start taking creatine without checking with your doctor first.

9. Vitamin E

Vitamin E is an antioxidant nutrient that is essential for healthy immune function and circulatory wellness. There aren’t any studies showing an impact for body weight or composition, but some early animal research notes a potential association between vitamin E, estrogen, and body fat. While human research is needed before conclusions can be made, this study noted that excessive vitamin E was associated with excessive body fat, not muscle building.

Vitamin E should be consumed as a balanced part of a healthy diet, but dietary supplements are unlikely to influence body composition or muscle building in a beneficial way.

10. Zinc

Zinc is a mineral that is needed for physiological wellness: immune system function, gastrointestinal health, cellular metabolism, and enzyme activation. Practically, zinc helps with wound healing, DNA synthesis (which has an impact on every cell in the body), and even normal smell sensory responses.

Zinc does not have a direct impact on weight gain or body composition, but because of its wide-reaching bodily impacts, it can certainly support healthy weight goals.

  • If zinc is inadequate, you may have an altered sense of smell, which affects how food tastes. It’s difficult to eat a diverse, nourishing food plan if your sense of smell is off.
  • Zinc plays a role in leptin, a hormone that is a modulator of body fat, appetite, and energy balance.
  • It can support healthy weight balance even outside of training or muscle-building, particularly in cases where health-related factors are involved with unintentional weight decreases.

People who eat vegan or vegetarian diets may be at a higher risk for inadequate zinc intake. Pregnant and lactating people, as well as anyone who has gastrointestinal or other conditions, may also have higher needs. Zinc dietary supplements can support food intake and maintain healthy digestive enzyme function.

11. Magnesium

Magnesium is a mineral that plays a role in lots of things, but muscular comfort and bone health are two angles that get the most attention. Magnesium on its own won’t lead to weight gain or adjustments to body composition. But inadequate intake is associated with physical discomforts, like muscle cramps, and even lower quality sleep. Meta-analysis and systematic review do not support magnesium supplement benefits for people who already have adequate status, but it may have more notable support for people with inadequate intake, older adults, and people who consume higher intakes of alcohol.

The RDA is between 310-400 mg for non-pregnant adults. While it is found in many foods like pumpkin seeds, chia seeds, almonds, spinach, cashews, and edamame, many adults do not reach the optimal intake. Magnesium can be taken on its own and is commonly found in multivitamins.

12. Probiotics

Probiotics get a lot of attention for how they support the microbiome and immune system. The diverse landscape of bacteria that populate the gut also have a role in body weight, but not in a way that can be directly altered by taking supplements. The best way to support body weight with probiotics is to eat a balanced diet with plenty of food variety. By nourishing a healthy gut, you will support overall well-being through digestive function, nutrient absorption, detoxification, and elimination.

You can get probiotics from fermented foods like sauerkraut, kimchi, sourdough bread, and kombucha. Probiotic supplements can support gut diversity, but don’t replace the importance of a healthy diet that nourishes your microbiome.

13. Calcium

Calcium is a mineral that is vital for musculoskeletal strength. It supports healthy bones and aids in healthy muscle contraction. The most notable impact of calcium on body composition is its impact when the nutrient is out of balance, either from too little or too much. A meta-analysis of randomized controlled trials did find that calcium from dairy foods does have an impact on body composition: while it produced no change in body weight, it led to a greater reduction in body fat alongside calorie reduction. The same research found no benefit of calcium supplements alone for weight loss, but that 3 servings of dairy per day were beneficial for fat loss.

If you consider the impact of food-based calcium on body composition, it could also generally support healthy muscle and adipose tissue balance, even in people seeking to increase their weight. Calcium-rich foods also contain protein, healthy fat, and other nutrients that may not be found in dairy-free or low-fat alternatives. Studies need to be done for this specific purpose, but overall, calcium is a nutrient of importance for everyone, regardless of body composition or health goal.

You can get calcium from dairy products as well as collard greens, sardines, sesame seeds, kale, and mustard. Dietary supplements support overall intake if you cannot get enough from foods, but it’s best to spread calcium throughout the day to facilitate optimal absorption since the body can only absorb so much at one time. More calcium is absorbed when consumed at 500 mg or less at a time. Vitamin D and vitamin K also support improve calcium absorption in the intestines, which is why the Care/of calcium supplement includes these nutrients together.

Why vitamins are important when trying to gain weight

When you are trying to support healthy weight gain, this is most often successfully done by adding muscle mass. Your body builds muscle in response to exercise and training, but relies on nutrients to provide these building blocks. Protein and amino acids are the main elements needed to increase muscle, but vitamins fuel many aspects of cellular, physiological, and metabolic function. Without an adequate intake of vitamins, your body may not be able to efficiently transport nutrients in your body or utilize food for energy purposes.

How to gain weight naturally

Weight is affected by many factors. It is not a simple equation, and it is also essential to understand that genetics, age, stage of life, health conditions, diet, and activity level can all affect how you gain weight.

Some basic principles that apply to natural weight gain include:

  • Increase your daily energy intake (calories) from foods, focusing on more protein and healthy fats
  • Eating more frequent meals, such as every 2-3 hours, instead of going longer periods between food
  • Engaging in regular physical activity, particularly resistance training, weight training, or weight-bearing exercises (like yoga, dance, walking, tennis, gymnastics, jogging, and more)
  • Supplement your daily meals with smoothies, protein shakes, and other nutrient-dense snacks for extra daily energy
  • Make sure you are properly hydrated
  • Get a good amount of high-quality sleep

Factors that may contribute to weight gain challenges

Certain things might make it harder to gain weight, or keep weight on. These may include:

  • Age
  • Physical activity level
  • Food and nutrient intake
  • Gastrointestinal health and ability to absorb nutrients
  • Resting metabolic rate (RMR)
  • Tobacco use
  • Alcohol use
  • Certain chronic conditions
  • Neurological challenges
  • Some hormonal imbalances

If you have trouble gaining weight, or notice that you are losing weight when you don’t intend to, it’s important to see a healthcare provider immediately. This could be a sign of a serious underlying condition.

Mental and emotional stress

Stress, overwhelm, burnout, and perpetual emotional exhaustion can all make it hard to maintain a healthy weight. While more research points to these factors as a trigger for weight gain, others may find it hard to eat regular meals, maintain a healthy appetite, or prioritize general wellness that could result in weight loss.

Regardless of your health goals, it’s important to have positive ways to process stress and to recognize the signs of burnout so you can address them.

Certain medications

Medications that you may take for different reasons can have an affect on your body composition, appetite, and energy. While some medications have a side effect of leading to weight gain, others may be associated with side effects of weight loss even if that is not their intended treatment outcome, including:

  • Central nervous system stimulants
  • Antibiotics
  • Pain management medications
  • Certain antidepressants

Not everyone responds to medications in the same way. If you take a medication that is impacting your appetite or body weight, speak to your medical provider. Don’t stop taking medication without talking to your doctor.


Genetics play a role in literally everything that has to do with your health. But the direct cause-and-effect impact between your genes and your body weight are not so clear. Many genes produce enzymes or other chemicals, like neurotransmitters, that are influenced by environmental and dietary factors. This is referred to as epigenetics and nutrigenomics (or nutrigenetics).

You can’t fully control how your genes respond, but by prioritizing a healthy, balanced lifestyle, you can influence your genes to respond better than if you are undernourished, stressed, or sedentary.

Final Takeaways

Weight gain is not a simple formula. To support a healthy body weight, including a goal to increase muscle mass, there are many things to consider. Supporting a balanced intake of essential nutrients, like vitamins, won’t necessarily lead to direct weight gain. However, lack of access to nutrients can hinder health goals from a cellular, metabolic, or overall functional level.

Supplements alone are not the answer for a healthy weight plan, but when used alongside a nourishing diet, regular physical activity, healthy sleep, and proper hydration, they can support your overall goals.

You're unique.
Your supplements should be too.

Take the quiz