Medically Reviewed

Does Vitamin D Help With Weight Loss?

Vitamin D is an essential vitamin. While there is a relationship between vitamin D and weight, supplementation will not directly result in weight loss.

The debate over whether vitamin D aids weight loss is an ongoing one. Although many people believe that supplementing with vitamin D can lead to weight loss, it is not the quick-fix solution some make it out to be. Despite claims to the contrary, no hard scientific evidence suggests taking large doses of vitamin D represents a viable weight loss strategy. In this article, we will delve into the truth behind vitamin D and how it relates to weight.

What is Vitamin D?

Vitamin D is a fat-soluble vitamin that plays a significant role in the body. It functions like a hormone and helps to regulate calcium and phosphorus levels, which are essential for healthy bones, teeth, and muscles. Known colloquially as the "sunshine vitamin," under sun exposure our skin synthesizes vitamin D, offering up its various health benefits the natural way.

Vitamin D’s primary function is to maintain bone health by promoting calcium absorption in the gut and reducing its excretion by the kidneys. It also plays a vital role in immune health. However, recent research suggests that vitamin D has many other functions, too, including helping to strengthen muscles and improve muscle function. For instance, the results of this controlled trial indicates the potential for vitamin D to promote muscle restoration in those who had insufficient levels of vitamin D. Additionally, studies have found that vitamin D supplementation has the potential to promote upper and lower body muscle strength in those who are deficient. The best way to support muscle strength with the strongest scientific evidence is still through weight lifting or resistance training.

Vitamin D Deficiency and Weight

Findings from this study suggest a link between vitamin D deficiency and weight gain, observing a correlation in vitamin D deficiency and obesity.

In this systematic review and meta-analysis, an inverse relationship between the percentage of fat mass and vitamin D levels suggests a similar conclusion: that D deficiency and weight gain can, in some cases, go hand in hand. While the underlying factors remain unclear (precisely how D regulates weight), the research points to a few possibilities.

One finding is that individuals with greater amounts of subcutaneous fat (fat that is located just beneath the skin) might sequester greater amounts of D. As a fat-soluble, vitamin D is absorbed and stored in fat tissue. Thus, individuals who have more fat cells would likely require higher intakes of vitamin D to maintain normal levels.

By another explanation, the overweight may be getting less regular sun exposure, or reduced intake of vitamin-D-enriched, fortified foods.

Other symptoms of vitamin D deficiency

People all over the world are deficient in vitamin D. People who are overweight, have gone through certain gastrointestinal surgerical procedures, have dark skin, have limited sun exposure, or are older than 65 are at increased risk of vitamin D deficiency. The symptoms of vitamin D deficiency can be subtle or may not show up immediately, but over time they can become more apparent.

One of the most common potential symptoms of vitamin D deficiency is bone pain and muscle weakness; however, most people who are deficient or have suboptimal levels may not present with any symptoms at all. As an aid to calcium absorption, the vitamin D we get in food helps contribute in turn to strong bones, muscles, and joints. Reduced levels of vitamin D make it difficult to absorb calcium, leading to potential bone issues.

Alongside bone and joint issues, a D deficiency can also present as persistent feelings of fatigue, reducing energy levels and efficiency in the carrying out of daily tasks. That being said, fatigue is not a symptom exclusive to a vitamin D deficiency. In fact, it can be a result of a variety of potential factors or reasons. So if you are experiencing fatigue, be sure to talk to your doctor about potential underlying causes.

Does Increasing Vitamin D Levels Aid in Weight Loss?

While the media has been buzzing about vitamin D supplementation as a tool for weight loss, to date no hard evidence supports such a link. A clinical trial concluded that vitamin D supplementation in those who were deficient did not affect weight loss, but it was able to significantly promote overall health. Vitamin D supplementation for those who are clinically deficient can be a beneficial part of a weight loss plan as nutrient levels should be at an optimal level to promote optimal health., Unfortunately when vitamin D levels are optimal, supplementing with vitamin D will not directly result in weight loss.

Conversely, weight loss is achieved with a healthy plan consisting of nutrient-dense foods, fiber, veggies, fruits, exercise, adequate sleep, stress management, and proper hydration.

Does Weight Influence How Much Vitamin D is Needed?

As mentioned earlier, recent studies suggest that individuals who are overweight may require higher doses of vitamin D. This is likely due to the fact that increased fat cells would act as a storage site for fat-soluble substances, such as vitamin D, in turn making less of it available for use in the body. Thus, healthcare professionals are now taking body size into account when prescribing vitamin D supplementation.

However, studies have suggested that as individuals lose weight, serum vitamin D levels may begin to increase. Therefore, it is important to talk to your doctor about measuring your vitamin D levels periodically to ensure that your body is able to absorb and use vitamin D effectively. Always consult with your physician to figure out the appropriate dose of vitamin D.


The recommended daily allowance (RDA) of vitamin D varies depending on age and other factors. However, the average daily recommendation for adults between 19-70 years old is 15 mcg (600 IU), while adults who are 71 years or older would require 20 mcg (800 IU).

Just as a lack of vitamin D can contribute to various health concerns, , an excess of vitamin D can also be harmful. The current daily upper limits for vitamin D are 4,000 IU. Exceeding this daily intake from all sources – food and supplements – should be avoided, unless instructed by your healthcare provider. It’s important to note that sun exposure will typically not lead to vitamin D toxicity. Talk to your doctor to figure out the optimal dose for your health needs.

Other Ways to get Vitamin D

The most natural way to obtain vitamin D is through sun exposure. Researchers suggest that approximately 5-30 minutes of sun exposure, particularly between the hours of 10 am - 4 pm, either daily, or twice a week should lead to sufficient vitamin D synthesis. While sunlight is the primary source of vitamin D for our bodies, there are other ways to ensure you're getting enough of it.

Another way to get vitamin D is through food sources. Fatty fish like salmon, tuna, and mackerel can be excellent sources of vitamin D. Eggs yolks also contain some vitamin D, but only if the chickens have been fed a fortified diet.

You can also get more vitamin D by consuming beverages that are enriched with it. Many manufacturers add vitamin D to milk and non-dairy milk alternatives, such as soy or almond milk products. Orange juice also contains added nutrients such as calcium or vitamin D, so check the labels when shopping at your local supermarket.

The Bottom Line

The bottom line here is that while some studies have suggested a link between vitamin D and weight loss, the evidence does not support this notion. Yet, there is a clear, inverse relationship between vitamin D levels and body weight, indicating that people who are overweight tend to have lower levels of circulating vitamin D.

Therefore, maintaining adequate vitamin D levels through dietary sources or sunlight may play a role in weight management, but vitamin D supplementation alone is not a reliable method for weight loss. At the end of the day, there is no quick fix when it comes to weight loss. The gold standard for healthful weight loss or weight maintenance comes down to a balanced diet, regular physical activity, and stress management.

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