Can Vitamin D Deficiency Cause Weight Gain?

Struggling to lose weight? If so, it may be due to more than just diet and exercise as new studies reveal that it may be possible for a vitamin D deficiency to cause weight gain.

New research shows the problem might not be how much you’re eating or even whether or not you live an active lifestyle. Instead, science has identified a link: that mild to moderate Vitamin D deficiency causes weight gain – especially belly fat. We’ll tell you what you need to know about why it happens, how you can prevent it, and how you can stay well right now.

What is Vitamin D?

Before we get into the science of Vitamin D and if it can cause weight gain, let’s talk about what this simple substance really is – and isn’t.

First, the term “vitamin D” doesn’t actually refer to any single chemical or molecule. It instead encompasses a short list of fat-soluble secosteroids. The most common and essential of these are D3 (cholecalciferol) and D2 (ergocalciferol).

As a nutrient, all of the “D” vitamins influence, enhance, or modulate the digestion of key electrolytes and nutrients from food – primarily, calcium, magnesium, and phosphate. These are, in turn, responsible for nearly every aspect of daily existence, including:

• Respiration
• Heart rate
• Muscle movement
• Even how effective your liver and kidneys are at clearing away waste

The human body produces Vitamin D when exposed to sunlight. This process starts when 7-dehydrocholesterol (7-DHC) stores within the skin are absorbed and transformed into a precursor hormone called previtamin D3. This, in turn, is then again transformed into a more holistic form of Vitamin D.

Some people (especially true redheads) produce more vitamin D than others, and need only minimum exposure (around four minutes in the summer) to achieve recommended daily levels. Others seem to be less effective at producing previtamin D3, and might need up to seven minutes in the sun. This is just one of the many reasons why it’s important to eat foods rich in D.

How Does Vitamin D Affect Weight Gain and Metabolism?

Vitamin D’s impacts on metabolism probably have a lot to do with the fact that calciferol and ergocalciferol both modulate digestion. They don’t directly influence metabolism per se… but they do make it easier or harder for you to absorb critical metabolic nutrients like calcium, magnesium and phosphate.

Without enough Vitamin D, your body cannot uptake these nutrients correctly, and that might make it harder for you to benefit from the foods you eat.

Studies have also shown that getting enough D in your diet might help to reduce issues like insulin resistance. While there is no conclusive evidence to show why this is the case, it does make Vitamin D a potential and promising option for patients with PCOS and Type II Diabetes. Still, we don’t know enough about it to call it a fix.

A pair of studies also looked at fat stores in women and children and cross-examined their levels of vitamin D. In both cases, people who had lower levels (or even true deficiencies) were shown to have a higher body fat content than those who maintained adequate levels all throughout the study. More research is needed to identify exactly how this connection works or why it exists in the first place.

Nearly all research into Vitamin D and weight gain does support at least a potential link between deficiencies and excess belly fat. Given that this is one of the stickiest and most difficult areas to target, it may be advantageous for anyone who struggles with weight gain or loss to have their levels tested.

Common Signs of a Vitamin D Deficiency

A Vitamin D deficiency can affect weight gain, but the only real well to test your level of vitamin D is to have a blood test (we’ll talk more about that in a moment). However, there are certain signs that may indicate you have a problem. If you experience one or more of these symptoms, you should ask your doctor to order blood testing right away.

• Chronic infections and/or constant illness:

  Being sick frequently, even when you do your best to avoid it, might be a sign your levels are off. This is because calciferol plays an important role in immune function.

• Fatigue:

Having too little Vitamin D in your body can impact digestion and energy metabolism. This can produce extreme fatigue and exhaustion over time. Some patients report feeling “bone tired.”

• Joint and Muscle Pain:

Because all of the nutrients modulated by Vitamin D play such a major role in muscle function and digestion, chronic low levels might result in widespread pain. Low levels of magnesium are notoriously known for causing muscle spasms, aches, and pains.

• Depression:

Feeling sad all the time may not just be a product of a stressful life. Research shows that D deficiency may exacerbate depression or even trigger Seasonal Affective Disorder (SAD). This risk seems to be higher in patients who are overweight or morbidly obese.

• Weight Gain:

Yes, that’s right. Weight gain itself can be a symptom, especially if you’re having no luck with standard measures or if it comes up suddenly without warning. Your doctor can help you decide what weight qualifies as “overweight” for your individual body type.

Vitamin D deficiencies may produce other symptoms, like anxiety, brittle nails, or dry skin, in some patients. The most important takeaway here is that you should contact your doctor if you believe you have a problem – testing can help.

Testing Your Levels

Identifying your Vitamin D levels is really easy. Your doctor can order a simple blood workup to identify both your levels and rule out other possible contributing factors. In most cases, this shouldn’t take any more than about a week.

If a problem is identified, treatment is the next step.

How to Prevent (Or Fix) Low Levels

If you suspect you aren’t getting enough vitamin D, or you know you are deficient, you have options. Some of these, like simple diet changes and spending more time outdoors, are easy and “free” to access. Others, like injectable vitamin D or infusions, might come at a small cost but produce much faster results.

1. Diet Changes

Even though the human body produces vitamin D, it is still important to eat foods containing this important substance daily. Eggs, meat, cheese, and fatty fish (like trout or salmon) are all particularly high in this and several other key nutrients. You can also try switching out regular dairy milk for milk fortified with extra D.

2. Spending Time Outdoors

Spending more time outdoors may be the key for some people (especially those living in the northern hemisphere). However, the amount of time needed even for those who are deficient is still quite low at just 15 minutes of safe exposure. Consider this an “extra” that probably won’t hurt anything, but might not be enough alone.

3. Oral Supplementation

The easiest way to replace missing vitamin D is to supplement with an oral tablet, film, or liquid. D drops are available for both adults and children, and can be added to existing foods or beverages without changing flavors. For picky kids, chewable gummies may work better.

4. Injectable Vitamin D

In cases where D deficiency is severe, supplementation might not be enough. Your doctor might recommend an injectable vitamin D formula instead to speed along recovery and help get your body back on track. Even then, most patients are able to continue with oral supplementation rather than having frequent injections.

Common Vitamin D Questions

Can Vitamin D Cause Weight Gain?

A deficiency in Vitamin D affects how your body absorbs critical metabolic nutrients, making it harder to benefit from these foods. Studies have also shown those with a deficiency carry a higher body fat content than those without. Nearly all research has shown some sort of link.

Why is Vitamin D Important?

Vitamin D monitors the digestion of nutrients and electrolytes in the body: calcium, magnesium, and phosphate which in turn affect how your body functions.

Can You “Treat” a Vitamin Deficiency?

Yes. You can improve the levels of vitamins in your body. This may include simple diet and lifestyle changes, to oral supplements or injections.

Final Thought

Here’s what matters: weight gain is often a symptom of health issues, full stop. A vitamin D deficiency can cause weight gain, but it’s not the only reason. Whether you’re overeating due to stress or gaining due to a vitamin D deficiency, it’s important that you don’t force yourself to struggle in silence. Reach out to your pharmacist, physician, or care team – there’s a lot they can do to help.