Understanding Vitamin D Deficiency: Causes, Symptoms, and Remedies

Understanding Vitamin D Deficiency: Causes, Symptoms, and Remedies

Vitamin D is a fat-soluble vitamin essential to your bones, mental health, and sleep. 

Though it can be produced by the body from cholesterol when the skin is exposed to enough sunlight, more people lack this vitamin than you might believe.

The National Institutes of Health noted that as much as 1 out of 4 adult Americans can, to some extent, become the victim of vitamin D deficiency. Its symptoms vary with severity and age groups.

Adults are encouraged to aim to obtain between 15 and 20 micrograms (600-800 IU) of vitamin D in their daily diet. You must have enough vitamin D in your body to perform the various biological processes.

This article will dig into various causes of vitamin D deficiency, ranging from poor exposure to sunlight and dietary insufficiency to more elaborate causes such as genetic predisposition and the effect of chronic diseases.

Overview of vitamin D deficiency

Vitamin D is also termed the "sunshine vitamin," given its unique synthesis triggered by sunlight exposure, and it's more than just a nutrient—it's a vital component for maintaining bone strength by facilitating the absorption of calcium and phosphorus.

Its impact, however, isn't limited to bones. This vitamin is pivotal for a robust immune system, minimizing inflammation and ensuring smooth neuromuscular operations. 

Remarkably, vitamin D resembles a hormone in its function and is integral to cellular processes throughout the body, courtesy of ubiquitous cellular receptors tailored for it.

Our bodies can produce vitamin D naturally when our skin is exposed to the sun, with cholesterol as the building block.

How prevalent is the occurrence of vitamin D deficiency?

Unfortunately, vitamin D deficiency is not an uncommon health condition. According to some estimates, as many as 25% of Americans may be deficient in this vitamin.

It occurs when the body doesn't absorb or synthesize enough vitamin D over time. The leading culprit? Insufficient sunlight exposure. 

Very few foods are naturally rich in vitamin D, and fortified foods don't always hit the mark for daily requirements, so many are left deficient.

Vitamin D deficiency isn't a localized problem; it's an extensive global health concern affecting over a billion individuals across various ethnic backgrounds and ages. 

Much of the adult and younger population falls short of the necessary vitamin D levels. The issue is especially acute in areas with little sunlight or where cultural norms dictate extensive clothing cover, leading to increasing deficiency rates.

Research has highlighted a troubling prevalence of vitamin D deficiency among those residing at higher latitudes with minimal exposure to UVB light, particularly during the gloomy winter months.

However, it's not only the regions lacking generous sunlight that are affected. 

Even in sunnier locales, the trend of staying indoors, coupled with the diligent use of sunscreen to ward off skin cancer risks, has paradoxically contributed to a spike in vitamin D deficiency cases.

Who is most at risk of getting vitamin D deficiency?

Certain groups are more susceptible to severe vitamin D deficiency, such as: 

People with limited outdoor activity

Those in northern climates, indoor workers, individuals confined at home, and those who dress conservatively for cultural reasons are all at risk. Exposure to sunlight (especially UVB rays) for 5-30 minutes at least two times a week stimulates endogenous synthesis of vitamin D.

The aging population

With age, the skin's ability for vitamin D production decreases, as does the kidney's efficiency in activating the vitamin. 

Consequently, older adults, especially those over 70, are more susceptible to developing vitamin D deficiency and need dietary supplements.

Breastfed babies

Vitamin D levels in breast milk are typically modest, and without vitamin D supplements or adequate sunlight, these infants may not get enough. Exposing infants to mild sunlight frequently is important to help them produce the vitamin.

Individuals with high melanin skin content

A greater concentration of melanin impairs the skin’s ability to generate vitamin D from sunlight. So, people with darker complexion might find a need to supplement vitamin D.

People with specific health issues

Conditions that affect nutrient absorption, like Crohn’s, celiac disease, and cystic fibrosis, can significantly hinder vitamin D intake from food. If you have any of these ailments, it is crucial to get your vitamin D level checked.

Those with a higher body mass index (BMI)

Excess body fat stores vitamin D, limiting its circulation in the blood, making those with a BMI of 30 or above prone to lower vitamin D levels.

Individuals who take certain medications

Medications that alter vitamin D metabolism, such as certain anticonvulsants, steroids, antifungals, and HIV/AIDS treatments, can also heighten the risk of deficiency.

How do you diagnose vitamin D deficiency?

To confirm a suspicion of vitamin D deficiency, healthcare professionals turn to blood tests, with the 25-hydroxyvitamin D test being the gold standard. 

Levels below 20 nanograms per milliliter generally indicate a vitamin D deficiency, though expert opinions on this threshold vary.

Risk factors like skin tone, sunlight exposure, weight, age, and pre-existing medical conditions are scrutinized. Should the risk be significant, a blood test is often recommended.

In conjunction with blood work, your doctor might evaluate dietary vitamin D intake sunlight exposure, conduct a physical exam, and review medical history. 

They will be on the lookout for bone discomfort and muscular weakness—telltale signs of severe vitamin D deficiency, which, if unchecked, could progress to rickets in children or osteomalacia in adults.

Once a deficiency is confirmed, rectifying the imbalance involves a regimen of vitamin D supplements and lifestyle tweaks to increase sun exposure and dietary intake of the vitamin.

Understanding the nuances of vitamin D deficiency is paramount for maintaining optimal health. It's an often overlooked yet essential aspect of our well-being that affects our overall health.

Symptoms of vitamin D deficiency

Vitamin D deficiency symptoms often go unnoticed until various symptoms and health troubles surface. 

Recognizing these signs is pivotal because this nutrient is a cornerstone for everything from robust bones to a vigilant immune system.

Here are a few signs that indicate potential deficiency:

Subtle signs of a hidden vitamin D deficiency

The initial vitamin D deficiency symptoms are often mild and easily ignored. Here are a few examples that you should keep an eye out for:

Persistent fatigue

An ever-present weariness that lingers even after ample rest might hint at low vitamin D levels. It's a vague yet common complaint among those running low on this nutrient. Thus, one of the symptoms of vitamin D deficiency is fatigue

Aches in bones and back

Essential for bone fortification through calcium absorption, a shortfall in vitamin D can appear as a persistent, deep bone ache or a distinct tenderness in the lower back region.

Bone pain and muscle weakness

If muscles ache without explanation or don't seem to sustain strength, it could be a quiet alarm signaling a deficiency, often starting mild and escalating with time.

Emotional shifts and despondency

Links between lower vitamin D levels and mood swings, including depressive states, have surfaced, though the connection remains partially unclear. 

Lack of enough vitamin D might influence neurotransmitters, the brain's chemical messengers.

Delayed healing

Post-surgery or injury, sluggish wound recovery might indicate inadequate vitamin D, a key player in generating new skin cells for wound closure.

Weakening bones

Discovering reduced bone mineral density can signal that bones are leaching calcium and minerals, potentially pointing to insufficient vitamin D.

Unusual hair thinning

While stress is often blamed for hair loss, a severe drop in vitamin D is also a known culprit, especially when the loss is significant.

Increased infection frequency

A well-armed immune system is one of vitamin D's responsibilities. If colds or respiratory issues are recurrent, it might be time to evaluate vitamin D intake.

Critical conditions from chronic vitamin D deficiency

If vitamin D deficiency deepens without intervention, it can lead to more serious health conditions:


Mostly seen in children with critical vitamin D deficiency, rickets soften and weaken the bones, leading to deformities, primarily in developing regions.


In adults, a grave deficiency can lead to osteomalacia, where bones lose their density and firmness due to insufficient mineralization.


Indirectly, vitamin D scarcity can hamper calcium absorption, escalating the risk of osteoporosis, characterized by brittle, fragile bones.

Causes of vitamin D deficiency

Understanding what causes the deficiency of this vital vitamin is the best way to prevent this condition. Here are a few science-backed reasons for vitamin D deficiency:

Limited sunlight exposure

Our skin's ability to synthesize vitamin D from sunlight is our main route to meet our needs. However, several hurdles can prevent the optimum synthesis of vitamin D in your body, such as:

  • Your location: If you reside far from the sunny equator, especially during the dim winter months, you might make less vitamin D than your body needs.
  • Using sunscreen: We slather on sunscreen to shield ourselves from skin cancer, but this also slashes our skin's vitamin D production.
  • Staying indoors: Many of us are tethered to indoor life by our jobs or personal choices, reducing our chances to soak up the sun and plummeting vitamin D levels.
  • Clothing choices: Full-coverage outfits for cultural adherence or personal choice can effectively block those UVB rays the skin needs to produce vitamin D.

Dietary deficiencies

Vitamin D is naturally found in only a few select foods, and fortification doesn't always fill the gap. This is caused by: 

  • Plant-based diets: Vegans and vegetarians might be short on vitamin D since plants aren't big on this nutrient.
  • Removing dairy: If you avoid dairy due to intolerance or allergies, you might miss out on fortified vitamin D.
  • Dietary restrictions: Those with restricted diets or those who aren't getting their full, balanced diet might fall short on their vitamin D intake.

Absorption and metabolism issues

Sometimes, even a vitamin D-rich meal isn't enough if your body is unable or incapable of absorbing it, due to: 

  • Digestive problems: Issues like Crohn's, celiac disease, or cystic fibrosis prevent the absorption of fat-soluble vitamins, vitamin D included.
  • Organ issues: If your liver or kidneys are not working properly, they might not efficiently convert vitamin D to its active form.
  • Age: Your skin might not be as efficient in vitamin D production, and your kidneys might lag in processing it.
  • Obesity: When fat cells store all the vitamin D, it becomes less available for the rest of your body, requiring increased intake for equal blood levels.

Genetic issues and medicine interactions

Some folks might have a genetic predisposition that messes with how vitamin D is handled in the bloodstream and its activation in the body.

Furthermore, certain drugs like corticosteroids or seizure medications can also prevent your gut from absorbing or breaking down vitamin D.

Bariatric or weight loss surgery also affects your vitamin D absorption. Your smaller stomach after the surgery and altered intestines might not be as capable of absorbing food and vitamin D.

What are the potential complications associated with a vitamin D deficiency?

Left unchecked, a shortage of vitamin D in your system is like a silent alarm for your health, potentially setting off conditions that can shape your well-being. 

Here are some potential situations that can arise due to a chronic deficiency of this key vitamin:

Immune system dysfunction

Vitamin D helps with your immune system, increasing your defenses against infections. A deficiency of vitamin D causes an increased risk of catching infectious diseases like flu and TB.

Cardiovascular issues

Evidence suggests that not enough vitamin D might invite heart disease, stirring up concerns from hypertension to heart attacks. 

The association between vitamin D deficiency and cardiovascular disease is still in its early stages, but early indications point to a negative relationship.

Cognitive impairments and neurological disorders

Vitamin D receptors are present in the brain and spinal cord, hinting that this nutrient could keep cognition sharp and fend off disorders like Alzheimer's. A vitamin D deficiency is also implicated in mood disorders and depression.

Metabolic disorders

Diabetes and obesity have also been linked to vitamin D deficiency. While the relationship is still being pieced together, some studies suggest that lack of vitamin D might interfere with insulin and blood sugar control.

Auto-immune disorders

Vitamin D keeps the immune responses in check. Without it, you might see an increase in conditions where the body fights itself, like type 1 diabetes, multiple sclerosis, and rheumatoid arthritis.

Pregnancy-related complications

For expecting mothers, a vitamin D shortage can complicate the journey with risks like preeclampsia and gestational diabetes. There’s also evidence about vitamin D’s role in the baby’s bone development and overall health down the road.

An unmitigated vitamin D deficiency in pregnancy might cause potentially dangerous complications for both the mother and the unborn child.

Treatment of vitamin D deficiency

Fortunately, treating and reversing vitamin D deficiency and preventing associated health complications is possible. 

You can treat vitamin D deficiency by:

  • Consuming foods rich in vitamin D, such as fatty fish, egg yolks and fortified dairy products.  
  • Increasing your exposure to sunlight by spending time outdoors, especially during morning hours. 
  • Taking vitamin D Supplements.

What is the typical duration for recovering from a vitamin D deficiency?

Restoring vitamin D levels is a personalized journey. For some, it's a few weeks; for others, several months. 

It's about how low your levels have dipped and your body, including how well you absorb this nutrient. 

Your overall health also affects how quickly or not you restore your vitamin D levels.  

Daily vitamin D supplements like Why Not Natural’s Organic Vitamin D3 With K2 capsules will do the trick if you are very low on this vitamin. The Vitamin D3 with K2 synergistic blend enhances calcium absorption, promoting bone health. 

All organic ingredients effectively address vitamin D deficiency with natural, holistic support.

But note that you should always talk to your doctor before starting any vitamin or other dietary supplementation.

When is it advisable to consult a doctor regarding a vitamin D deficiency?

Not sure if you should ring up your doctor about vitamin D?

Here’s when consulting with your doctor is a good move:

Presence of symptoms

If your bones are achy, muscles weak, or you are feeling blue, these could be your body’s way of indicating a vitamin D deficiency.

At-risk individuals

Older folks, those with darker skin, people with a vegan lifestyle, or anyone bundled up away from the sun might need a professional check-in to determine their vitamin D levels.

Health problems

If you are juggling health issues like brittle bones or your kidneys are malfunctioning, a  visit to a doctor might help you reveal your vitamin D status.

Expecting or nursing

For mothers and mothers-to-be, having enough vitamin D in your body is crucial. It is a great idea to talk to your doctor about your levels when you are pregnant or thinking of conceiving.

Prevention of Vitamin D deficiency

Keeping optimal vitamin D levels is more than just health maintenance; it’s a lifestyle. Think of it as a daily dose of wellness that improves your bone health and keeps your spirits high.

Here are some tips on how to keep those vitamin D levels from dipping too low:

Embrace the sun

About 10 to 30 minutes of midday sun can work wonders, depending on your skin, global location, and the season. Remember, while your skin is busy making vitamin D, it’s also radiated with sun rays. So, after that initial sun bath, slap on some sunscreen to get the best out of your sun exposure.

Maintain a healthy diet

Your diet can be a great way to maintain healthy vitamin D levels. Include foods like fatty fish, eggs, and mushrooms in your diet. And while you are browsing the grocery aisles, keep an eye out for fortified milk, orange juice, and breakfast cereals.

Get vitamin D testing regularly

Knowing your vitamin D levels now and then can keep your levels in the optimum range. Catch a deficiency early, and you can conduct dietary tweaks or vitamin D supplement additions to get back on track.

Takeaway: Reclaim wellness from Vitamin D deficiency with Why Not Natural

Vitamin D deficiency can slip under the radar with its understated signs, yet it packs a punch with potential serious health fallout if neglected.

Turning things around can be as simple as a dose of extra sunshine, a tweak to your menu, or a personalized vitamin D supplement plan, depending on your unique health challenges. 

The journey to replenish your vitamin D might differ from others, underscoring the importance of professional health advice at the first hint of an issue or if you think you might be prone.

Check out Why Not Natural Organic Vitamin D3 Liquid Drops with vitamin K2. These vitamin D supplements are a game-changer for anyone looking to boost their vitamin D levels. They are easy for your body to absorb, ensuring you get all the goodness without hassle.

Don't forget to subscribe to our newsletter to learn which supplements to take, how to combine them for maximum benefit, and other health tips to boost your energy and vitality. Plus, discover natural strategies to reduce hormonal imbalances, stress, and anxiety. Click here to get started!

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