What is Vitamin D?

Vitamin D is crucial for overall health and strong healthy bones, though many people continue to overlook it. If you and your loved ones want to avoid illness, improve well being, and establish a healthier lifestyle, then vitamin D will play a crucial part in the process. Not only is vitamin D great for helping your immune system fight infection, but it’s also a factor in ensuring your heart, muscles, brain, and lungs work the way they should. By understanding the facts about vitamin D, including what it can do for your body, what it is, the danger of deficiency, and how to get more of this substance into your system, you can achieve a healthier body.

The Nature of Vitamin D

Vitamins are chemicals that are essential for good health. They ensure that your body is able to heal properly, fight off illness, and work at its best. In simple terms, vitamin D is a type of vitamin that is present naturally in a small number of food substances, added artificially to others, and can be available in the form of a dietary supplement. Perhaps the primary factor that sets vitamin D apart from other vitamins is the fact that the body may create it endogenously when ultraviolet rays are absorbed from the sun, into your skin, triggering vitamin D synthesis. Another aspect that makes vitamin D unique, is that when your body gets it, it turns the substance into a hormone, known as calcitriol.

The vitamin D that you do get, regardless of the source it comes from, must be filtered and changed a number of times before the body can use it. Once this process is complete, your body uses the vitamin to regulate the amount of calcium in your bones, blood and gut, while helping cells throughout your body to communicate more efficiently.

What Vitamin D Can Do For Your Body

Many years ago, scientists began to recognize the link between vitamin D and strong, healthy bones. The realization came from the fact that sunlight, which allows for the production of vitamin D, or taking cod liver oil, which is rich in vitamin D, can help to prevent a bone condition known as “rickets” in children. The reason for this is that phosphorous and calcium are crucial for developing the strength and structure of bones, and vitamin D is required for the absorption of these minerals. Even if you eat foods that are rich in phosphorus and calcium, without enough vitamin D, your body will not be able to process them.

Today, a healthy supply of vitamin D is considered to be essential to good health, and important not just for the health of bones, but improved overall health too. Recent research has begun to show that vitamin D may, in fact, be an important factor in preventing and treating numerous long-term health problems. Some of the crucial functions of vitamin D include:

• Improved immune system – essential for fighting off infection
• Better muscle function
• Heightened cardiovascular performance
• Healthier respiratory system
• Brain development
• Anti-cancer potential

How Vitamin D Works

When you expose your skin to the sun, it starts a natural reaction which produces vitamin D, which is sent directly to the liver. At the same time, if you eat foods that contain vitamin D, or take supplements, that vitamin D is also sent to the liver, where it is changed into a substance known as “25(OH)D”. Commonly, if your vitamin D levels are measured, you will get results according to the amount of 25(OH)D present in your blood. The chemical produced is then transported throughout the body, where different tissues begin to turn it into activated vitamin D, or calcitriol, which works to help in the communication between cells, and manages calcium levels in the bones, gut and blood.

Crucially, getting the right amount of vitamin D isn’t related largely to the types of foods you eat. Rather, to get enough vitamin D, health experts often recommend that individuals focus on exposing their skin to sunlight regularly. If the body is unable to obtain the right amount of vitamin D as recommended by current guidelines, this can lead to vitamin D deficiency. A deficiency in your levels of vitamin D can sometimes cause serious conditions, such as osteomalacia in adults and rickets in children, which are conditions that lead to brittle, soft bones. What’s more, a lack of vitamin D has also been linked to numerous other conditions, including type 2 diabetes, cancer, asthma, Alzheimer’s, depression, and high blood pressure, as well as autoimmune diseases like Crohn’s, type 1 diabetes, and multiple sclerosis.

Vitamin D Benefits

Simply considering the functions of vitamin D should be enough to establish that it is a valuable substance, with a key role to play in the maintenance of good health. However, establishing a better understanding of how Vitamin D can work to improve your well-being can be beneficial when it comes to considering your dietary intake and sun exposure levels. For instance, according to a study published by the Journal of the American Medical Association, vitamin D reduces risks of multiple sclerosis. At the same time, this vitamin can reduce a person’s chances of suffering from heart disease and help to reduce their likelihood of suffering from common illnesses like the flu.

Vitamin D contributes to the development of healthy bones. For most people, when the concept of “strong bones” comes to mind, calcium is the number one mineral that people think of. However, it’s important not to overlook the impact of vitamin D. Research constantly shows that this vitamin is a stimulator of calcium deposition in bones, which makes them stronger and healthier. Another benefit of this vitamin is that it can improve muscle function. Studies have found that vitamin D deficiency is commonly associated with atrophy and muscle weakness, specifically in relation to type 2 muscle fiber atrophy.

While the primary function of vitamin D is to increase the absorption of calcium and maintain proper bone health, it’s worth noting the protective effect it has not only on your heart, but your ability to avoid other diseases. Recent evidence suggests that individuals with a deficiency in this vitamin are at an increased risk for heart disease, high blood pressure, sudden cardiac arrest, and heart failure. What’s more, a regular supply of vitamin D in your system can lead to a decreased risk of type 2 diabetes. Diabetes can lead to significant complications over the long-term, including heart disease, nerve damage, vision loss, kidney failure, and eye damage.

Perhaps even more significantly, obtaining the right amount of vitamin D, can significantly reduce your risk of suffering from many different kinds of cancer, including breast, ovarian, colon, and prostate cancer. The reasoning behind this is that Vitamin D is one of the most potent inhibitors of cancer-cell growth, reducing the chances of suffering from cancer, by contributing to cell differentiation and calcium absorption, as well as lowering the chances of metastasis – a process which allows cancerous cells spread from one organ into another.

Recommended Vitamin D Intake Amounts

The Food and Nutrition Board (FNB) at the Institute of Medicine of the National Academy of Medicine provides a set of intake references for nutrients like vitamin D in a list known as the “Dietary Reference Intakes” (DRI). DRI is the general term used for a set of reference values that can be used to assess and plan nutrient intake for healthy living. Importantly, these values are varied according to gender and age.

An RDA has been established by the FNB for vitamin D, which represents the amount that a healthy person should get each day to maintain normal calcium metabolism and bone health in healthy people. The RDAs for vitamin D are listed in “International Units”, or IU, and 40 IU is equal to a single microgram.

RDAs for Vitamin D

Age  Male  Female
0-12 months  400 IU  400 IU
1-13 years  600 IU  600 IU
14-18 years  600 IU  600 IU
19-50 years  600 IU  600 IU
51-70 years  600 IU  600 IU
Over 70 years  800 IU  800 IU

Although sunlight is the primary source used to obtain Vitamin D for most people, the above table of recommended dietary allowance is based on a minimal amount of sun exposure.

The Symptoms and Consequences of Vitamin D Deficiency

Most people get all of the vitamin D that they need simply be eating a healthy, balanced diet and getting some regular sunlight exposure. However, the U.S. Department of Health generally recommends a daily supplement for vitamin D to people in certain groups. For example:

• Children between the ages of six months and four years
• Pregnant and breastfeeding women
• People over the age of 65
• Individuals who do not receive the right sun exposure

The most common consequences of failing to get the right amount of vitamin D are osteomalacia in adults and rickets in children. However, these are not the only problems associated with vitamin D deficiency. The consequences of such a deficiency are actually numerous, and include metabolic disorders, skeletal diseases, cancer, autoimmune disease, cardiovascular diseases, cognitive disorders, infections, and mortality.

Some common signs of vitamin D deficiency include:

1. Darker skin – African Americans are at greater risk of vitamin D deficiency because people with dark skin need up to ten times more sun exposure to produce the same recommended levels of vitamin D.

2. Depression or sadness – serotonin rises with exposure to bright lights and falls with decreased amounts of sun exposure. Individuals with low levels of vitamin D are significantly more prone to depression.

3. Age – if you are 50 or older, your skin is less likely to produce much vitamin D in response to sun exposure. At the same time, your kidneys will be less efficient at converting vitamin D into the active form used by your body

4. Aching bones – vitamin D deficiency can lead to symptoms of osteomalacia, which lead to fatigue and aching sensations within the bones.

5. Sweating – one of the classic signs of a vitamin D deficiency is a sweaty head, and doctors still sometimes ask mothers about head sweating in newborn children to check for such a deficiency.

How to Get More Vitamin D in Your System

The best way to get the right amount of vitamin D into your system on a regular basis is to ensure you’re frequently exposed to sunlight. Because of the risk associated with skin cancer, there isn’t an official recommendation in circulation that suggests catching more rays. However, a small amount of regular sun exposure using protection can be helpful. Keep in mind that the sun is less likely to produce the daily requirements your body needs when it is at higher latitudes, or further away as a result of the winter season. What’s more, it’s important to note that simply sitting next to a window will not work.

Aside from sun exposure, individuals can get vitamin D using supplements or certain food sources. For example, the following table shows the IU per serving for certain foods, and the percentage of your daily value each food contributes to.

Food  IU per Serving  Percentage of DV
Egg (1 large) 41 10.00%
Liver (3 ounces) 42  11%
Sardines (2) 46  12%
Margarine (fortified 1tbsp) 60  15%
Yogurt (6-ounces) 80  20%
Milk (1 cup – vitamin D fortified) 115 29.00%
Orange juice (1 cup- Vitamin D fortified) 137  34%
Tuna (3 ounces) 154  39%
Salmon (3 ounces) 447  112%
Swordfish (3 ounces) 566  142%
Cod liver oil (1tbsp) 1360 340.00%

Often the best way to ensure that you’re getting the right amount of vitamin D on a daily basis is to commit to a healthy combination of regular (safe) sun exposure, combined with a carefully fortified diet, and potentially the addition of supplements. If you believe supplements may be beneficial to you, then it could be worth speaking to a doctor about the options that are available. Some health experts will actively recommend supplements to individuals who have low levels of vitamin D in their system.

Resources and References:

NIH Fact Sheet on Vitamin D for Health Professionals – Provides basic information about Vitamin D for health professionals. (NIH.gov)
Benefits of Vitamin D – Simple information about the benefits of Vitamin D. (Healthline)
Basic Info on What Is Vitamin D – General information about what vitamin D is and how it works within the body.
Benefits of Vitamin D – Various benefits of vitamin D. (Bodybuilding.com)
Vitamin D Deficiency and Its Symptoms – Vitamin D deficiency consequences and its symptoms. (MedicineNet.com)