Vitamin D3 Dosage for Weight Loss

  • By Abigail Roberts
  • 6 minute read
Vitamin D3 Dosage for Weight Loss

Vitamin D is a vital nutrient that has powerful health benefits, from supporting immunity to strengthening bones, teeth, and muscles. All adults and children above the age of 12 should be focused on getting an adequate amount of vitamin D per day (at least around 600IU).

Vitamin D is found in some foods but is mostly obtained through sun exposure and supplements. As it can be difficult to obtain through food sources, deficiency can be quite common, especially during winter months where sunlight is limited.

Low vitamin D can contribute to a whole host of health issues, including joint problems, depression, hair loss, fatigue, low bone density, and muscle pain.

Though, surprisingly, a lack of vitamin D intake can also affect your weight. This article takes a closer look at the link between vitamin D and weight, and how certain vitamin supplements may help you manage your weight better.

What is Vitamin D?

Vitamin D is a key nutrient that is involved in many bodily processes, including calcium and phosphate absorption, which are two of the main nutrients necessary for healthy bones, muscles, and teeth.

Vitamin D occurs naturally in small amounts in foods such as egg yolks, liver, red meat, and oily fish, and also fortified food products such as juices, spreads, and cereals.

Vitamin D is also referred to as the “sunshine vitamin” as our body naturally produces it from cholesterol when we expose our skin to the sun’s UVB rays.

This is often why it’s recommended to get outside for some sun exposure every day, or at least a few days a week, as you can naturally produce vitamin D spending even just 5 minutes in the sun.

What Does Vitamin D Do?

Vitamin D is one of the most beneficial micronutrients. It has been found to offer a range of health benefits, including:

Strengthening the immune system

One of the most well-known benefits of vitamin D is its ability to keep the immune system robust, helping you to fight off bacteria and viruses. This is because vitamin D is directly involved with T-cells and B-cells, the disease-fighting cells.

A lack of vitamin D can be one of the major contributors to developing illnesses, so it’s important to ensure you are taking in an adequate amount of vitamin D each day.

Promoting intestinal absorption of calcium and phosphorus

One of the key roles of vitamin D is regulating the absorption of calcium and phosphorus, which are vital minerals for bone health.

These nutrients are absorbed from the food we consume, but our digestive system isn’t quite cut out for getting the full job done regarding absorption. This is where vitamin D comes in to help.

Thus, vitamin D plays a key role in ensuring our phosphorus and calcium levels are where they should be, helping to maintain strong and healthy muscles, bones, and teeth.

Supporting oral health

Following on from the above point, it goes without saying that vitamin D contributes to the support of oral health. This is because of the role it plays in regulating phosphate and calcium, both of which promote the formation of healthy and strong teeth, as well as lowering the risk of gum disease and tooth decay.

Receive unique insights, advice and exclusive offers.
image of Performance Lab® capsules

Warding off anxiety, depression, and low mood

Anxiety, depression, and low mood can sometimes be attributed to low vitamin D levels, according to some research.1 It has been shown that vitamin D may help stave off depression, alleviate symptoms of anxiety, and help regulate mood.

Vitamin D Deficiency

It can be difficult to obtain enough vitamin D through diet and sun exposure alone, which is why it’s often recommended to take a supplement to bridge any potential gaps, particularly during the winter months.

This is especially true for certain groups that are more prone to low vitamin D levels than others, such as obese and overweight people, the elderly, and those who stay indoors often.

Vitamin D deficiency may put you at risk of many health issues, such as:

Increased risk of sickness

One of the biggest benefits of vitamin D is the role it plays in ensuring your immune system is strong and functioning properly, helping to fight against disease-causing viruses and bacteria.

If you find it difficult to shake off illnesses such as the common cold and flu, vitamin D levels may be something to take a closer look at.


Excessive tiredness and fatigue are common symptoms of many nutrient deficiencies, especially vitamin D.

Lower back and bone pain

Vitamin D plays a key role in bone strength and overall bone health, so, unsurprisingly, a lack of this nutrient could lead to bone issues.

Mood problems, depression, and anxiety

There have been noted correlations between low vitamin D and depression, particularly in older adults.

Vitamin D Deficiency and Weight Gain: Is There a Link?

The link between vitamin D and weight gain is still in its early stages, though there have been some interesting connections shown.

Firstly, being obese is a common risk factor for vitamin D deficiency, and a higher body fat percentage could potentially be linked to lower vitamin D levels in the blood.2

However, experts also have many other theories around this. Some experts state that overweight and obese individuals are typically less likely to eat foods that do not contain vitamin D, which others suggest that obese and overweight people tend to stay indoors more often, thus depriving their skin of direct sunlight.

Alongside this, vitamin D deficiency can possibly lead to weight gain in several ways:

Vitamin D deficiency and fatigue

Fatigue is one of the biggest contributors to weight gain. While this is often associated with the improper functioning of the thyroid, which can cause fatigue and weight gain, there is also something to be said for vitamin D levels.

Lack of vitamin D levels can cause tiredness and fatigue, which can leave you without the energy and motivation to exercise or stick to a physical activity routine.

Vitamin D deficiency and loss of bone density

As mentioned, vitamin D plays a vital role in bone health. Thus, low bone density is often related to low vitamin D levels, alongside other bone disorders, such as osteoporosis.

Low bone density can put you at risk of fractures, bone pain, and other joint issues, making it very difficult to stay physically active and lose weight.

Low Vitamin D and weight gain and depression

The relationship between depression, low metabolism, and poor weight management is a well-documented area of research. Depression and stress could be signs of low vitamin D levels, which may also explain the relationship between low vitamin D intake and weight gain.

To summarise, low vitamin D levels or deficiency may be indirectly linked to poor weight management due to the increased risk of developing depression, bone and joint issues, and tiredness and fatigue.

Though there is a difference between correlation and causation, and a direct link between vitamin D deficiency and weight gain is yet to be identified.

Can Vitamin D Help Weight Loss?

The correlation between low vitamin D and poor weight management is undeniable, but does this mean that vitamin D supplements can help you keep some weight off?

The simple answer is yes, vitamin D supplementation may improve your likelihood of decreasing body fat percentage and sticking to a weight management program.

This is mostly due to the influence vitamin D has on the production of certain neurotransmitters such as serotonin. This is known as the “feel-good” hormone, linked to a range of biological functions such as appetite, sleep, mood, and stress levels.

When your serotonin is at healthy levels, you feel more motivated, invigorated, and energized, making sticking to a weight loss program much easier.

Higher vitamin D levels have been associated with higher serotonin levels, as well as increased testosterone, a growth hormone linked to muscle mass and strength.

Vitamin D Dosage for Weight Loss

There is no specific recommended intake of vitamin D for weight loss. This is because low vitamin D intake is an indirect cause of weight gain, thus, it would make sense to simply follow the recommended daily intake of vitamin D to help address any low levels and possible deficiencies.

A general rule of thumb is that adults between the ages of 19 and 70 should take no less than 15mcg, which is equivalent to around 600IU. This should help bridge any gaps left by inadequate dietary intake, however, it is important to get your vitamin D levels checked by your doctor if you’re suspicious of a deficiency.


So, can vitamin D supplements help you lose weight? Well, studies do suggest a correlation between low vitamin D intake and weight gain.

While there are no specific recommendations around vitamin D supplementation and weight loss, it’s important to ensure you have an adequate intake of vitamin D through the diet, sun exposure, and supplementation to better your chances of improving weight management!


  1. Okereke, Olivia I, and Ankura Singh. “The role of vitamin D in the prevention of late-life depression.” Journal of affective disorders vol. 198 (2016): 1-14.
  2. Arunabh, Sonia et al. “Body fat content and 25-hydroxyvitamin D levels in healthy women.” The Journal of clinical endocrinology and metabolism vol. 88,1 (2003): 157-61.