The Real Reason for a Vitamin D Deficiency

author avatar Dr. Eric Berg 04/09/2024

While everyone knows that vitamin D is an important nutrient, not many people understand the signs of a deficiency.

Learn about the problems a vitamin D deficiency can cause, common symptoms, and what to do to prevent it.

The Role of Sun Exposure in Vitamin D Absorption

Sunlight is a crucial player in our body's vitamin D production. Skin exposed to the sun triggers the production of vitamin D, commonly known as the "sunshine" vitamin, with only 10 minutes providing approximately 1,000 international units (IU) of this essential nutrient.

Did you know 10 minutes of sun exposure can give you around 1,000 international units (IU) of this vital nutrient?

The Impact of Geographic Location on Vitamin D Production

Living closer to the equator gives you an advantage when absorbing sufficient amounts of vitamin D from sunlight. In these areas, there are more hours and intensity of daylight throughout the year.

Body Composition and Skin Type as Factors in Vitamin D Absorption

But not all bodies absorb sunshine's benefits equally. Higher body fat levels can reduce penetration by sun rays and hinder absorption rates. Those extra pounds could be standing between us and our dose.

Darker skin tones present another hurdle for optimal absorption because melanin reduces the amount of sunlight that can penetrate deeper layers, where synthesis occurs.

Vitamin D, infographics. Foods rich in vitamin D. natural products on white background

Dietary Sources of Vitamin D

It's no secret that our diets play a crucial role in maintaining healthy vitamin D levels. But getting enough from food alone can be a tough challenge.

The Importance of Fatty Fish in a Vitamin-D-Rich Diet

Fatty fish are a great source of vitamin D. Research indicates it's difficult, if not impossible, to get your daily dose unless you're consuming fatty fish regularly.

This surprising revelation emphasizes why we need more ways to ensure adequate intake.

Age-Related Changes in Vitamin D Absorption

As we age, our skin's ability to take in vitamin D lessens, as aging skin finds it harder to draw in sunlight for production of the nutrient.

The body naturally creates vitamin D when direct sunlight hits the skin. However, older adults may need more sun exposure than younger people to generate adequate amounts of this essential nutrient.

Aging affects your skin and influences other systems involved in vitamin D absorption. For instance, with age comes a decreased ability to convert absorbed or ingested vitamin D into its active form.

Dietary Adjustment Can Help

To counteract these changes and maintain healthy vitamin D levels, incorporating certain foods into your diet can help significantly.

Foods such as fatty fish (salmon and mackerel), fortified dairy products, or orange juice are good sources of dietary vitamin D. These might give you a fighting chance against deficiency due to aging-related absorption issues.

The Role of Liver Health and Bile Production in Vitamin D Absorption

The liver is essential for breaking down vitamin D, a fat-soluble nutrient, and subsequent absorption. A healthy liver is crucial as it helps produce bile, a substance needed to break down fats and let our bodies use them.

Bile production doesn't just rely on the liver, though. Our gut health also matters. A flourishing microbiome is necessary for the production of bile, helping us gain maximum vitamin D benefit from either sun exposure or our diet.

The gallbladder acts like an efficient storage system for bile, concentrating it so that when fatty foods come along (like those rich in vitamin D), enough bile can be released into your small intestine for optimal digestion and absorption.

If any part of this finely tuned system isn’t working correctly, absorbing sufficient amounts of vitamin D could become more challenging than you'd think.

Environmental and Genetic Factors Impacting Vitamin D Absorption

Clouds and other environmental factors can obstruct the body's ability to absorb essential nutrients by blocking sunlight.

Additionally, some people are born with defects in their vitamin D receptor (VDR). Because of these kinds of factors, people can struggle to intake enough vitamin D.

How Inflammation and Past Gut Problems Can Block Vitamin D Absorption

Your gut health also plays a vital role in absorbing vitamin D. However, past inflammation or gut issues may cause some holes in your digestive tract, making absorption more difficult.

External environments and inherited traits impact how effectively we utilize sunshine for its nutritional benefits.

Vitamin D illustration

Nutrition Deficiency Effects on the Body

Nutritional deficiencies can profoundly impact the body, affecting various aspects of health and well-being.

When we talk about the benefits of nutrients like vitamin D3, K2, and magnesium, it becomes clear just how vital they are in preventing these deficiencies.

Vitamin D3 is essential for strong bones, a healthy immune system, and overall vitality. When deficient, it can weaken bones, increase susceptibility to infections, and even mood disorders.

Similarly, vitamin K2 is crucial in directing calcium to the right places, ensuring it goes to the bones and teeth instead of accumulating in arteries.

A lack of vitamin K2 can contribute to cardiovascular issues and impaired bone health. On the other hand, magnesium is involved in hundreds of biochemical reactions in the body.

Its benefits include muscle and nerve function, blood glucose regulation, and bone support. When magnesium levels are insufficient, it can lead to muscle cramps, heart palpitations, and even issues with insulin sensitivity.

Understanding the benefits of these nutrients, vitamin D3, K2, and magnesium, highlights the importance of a nutritious diet to prevent the adverse effects of nutritional deficiencies and maintain optimal health.


Vitamin D deficiency is a widespread concern influenced by factors like sun exposure, diet, and age-related changes. While sunlight is a primary source, dietary sources like fatty fish play a crucial role, especially for those with limited sun exposure.

Understanding the impact of factors like aging, genetics, and gut health on absorption underscores the importance of a balanced diet and supplementation.

Deficiencies in vitamin D, K2, and magnesium can have far-reaching effects on health, emphasizing the need for proactive measures to maintain optimal levels and overall well-being.

By recognizing signs of deficiency and addressing absorption factors, individuals can take steps to ensure adequate nutrient intake and support their health. Consulting with a healthcare provider for personalized guidance is essential for developing an effective plan.

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