The Ins and Outs of D3 Vitamin

Plants aren’t the only living organism that can create nutrients with the help of the sun. Vitamin D is synthesized in the body from a chemical reaction between cholesterol and the sun to create cholecalciferol, otherwise known as the D3 vitamin. The D3 vitamin is one of four fat-soluble vitamins, but the only vitamin that can be taken in through the sun. While it is produced in the body through direct sunlight exposure it can also be taken in through a few different foods and is essential for calcium and phosphorus absorption.

What is D3 Vitamin?

Among the five forms of vitamin D vitamin, D3 vitamin stands as the primary type. This vitamin is often referred to as the “sunshine vitamin” because of its ability to be synthesized in the body through the skin’s exposure to direct sunlight exposure. While D3 vitamin is a common source of the D vitamins it is not biologically active in and of itself. It has to be metabolized within the body before it can be utilized in the body.

This metabolic process takes place in two steps. First, within the liver, cholecalciferol is hydroxylated to 25 hydroxycholecalciferol, this is the storage form of vitamin D. Second, within the kidney, 25-hydroxycholecalciferol yields 1,25-dihydroxycholecalciferol, which is the biologically active form of vitamin D.

D3 Vitamin From The Sun

Approximately 80 to 90 percent of the D3 vitamin in the body comes from exposure to sunlight. It is a common misconception that it is necessary to burn or tan the skin in order to get the adequate amount of D3 vitamin through sunlight. In fact, you only need to expose your skin to the sun for around half the time it would take for you to burn. Therefore, if it generally takes you an hour to burn then you only need about 30 minutes of sun exposure to get an adequate amount of D vitamin. The more surface area of skin that is exposed, the more vitamin D vitamin your body will produce.

Due to legitimate concerns for skin cancer and aging skin from exposure to sunlight, there has been a rise in sunscreen, extra clothing, and avoiding the sun altogether many people are not getting enough D3 vitamin through sunlight. The darker the skin the less likely a person is to get enough D3 as well.

Getting D3 Vitamin From Food

Sunlight is not the only way to get D3 vitamin into the body. While there are only a few vitamin d-rich foods for sources of D3 vitamin some foods can also be fortified with this important vitamin as well. Fortification refers to adding a vitamin or mineral to a food that is not there naturally. This is a great method that allows vitamins and minerals that would have been otherwise insufficient in the diet to meet the needs of an individual. It is especially important for D3 as vitamin d-rich foods for this vitamin are limited.

Foods that naturally contain D3 vitamin are egg yolks, beef liver, fatty fish, and cheese. Fatty fish that contain high amounts of vitamin D include tuna, salmon, and mackerel. Foods that are commonly fortified with vitamin D3 include orange juice, cereals, yogurts, and milk. However, because it can be difficult to take in enough D3 vitamin through food or sunlight it may be necessary to take supplements.

Getting D3 Vitamin From Supplements

When the D3 vitamin is taken in through supplementation it is either in the form of D2 also known as ergocalciferol or D3, which is being discussed, known as cholecalciferol. However, studies show that D3 is 85 percent more effective at raising vitamin D in the body than D2. Vitamin D3 as a supplement is also stored more efficiently in the body. A conversion process is required to get both forms, D3 and D2, into the active form of vitamin D in the body. But, converting D3 to the active form of vitamin D in the body is faster than the process for converting D2 to the active form.

The D3 Vitamin Benefits

There are few processes in the body that do not require vitamin D in some capacity. Vitamin D has the ability to impact overall health in many positive ways. Most notably, the D3 vitamin is used to assist the body in absorbing calcium and phosphorus, both of which are essential to maintaining healthy bones. This is why vitamin D, and fortified milk, in particular, is known for bone health. Some lesser known benefits of D3 include immune function, weight loss, and overall mood.

Immune system

The immune system is the body’s primary defense against illness of all forms. Many vitamins and minerals are responsible for strengthening this important system in the body and D3 vitamin is among them. A deficiency in vitamin D has shown to be congruent with an increase in autoimmunity and infection. Vitamin D receptors have also been found on immune cells which enable vitamin D to control adaptive and innate immune responses. To further prove this vitamin’s role in immunity, Vitamin D has a rich history in the treatment of tuberculosis both through sunlight and food sources, prior to the onset of antibiotics.

Multiple sclerosis (MS) is a chronic condition that affects the central nervous system. The immune system essentially attacks the protective covering of the nerves. D3 has been shown to reduce the risk of developing MS.

Heart disease continues to be a growing issue among adults. However, D3 is making positive impacts on the health of the heart. Not only may it prevent heart disease, but studies show that D3 may also reverse damage to the heart caused by heart disease. Low vitamin D has also been associated with an increase in heart disease.

Mineral Absorption

There are several factors that may lead to a decrease in calcium absorption in the gut. Insoluble fiber may play a role in blocking calcium absorption. However, D3 vitamin will increase both calcium and phosphorus absorption in the gut. These are both minerals that are essential to overall health. This mineral absorption benefit allows for the normal mineralization of bone and overall bone health.

Weight Loss

It is known that D3 vitamin will increase calcium absorption. This increase in calcium has an appetite suppressing effect which may lead to weight loss. For the person that is vitamin D deficient, correcting this deficiency may help them lose weight.

Taking in more vitamin D3 can lead to weight loss simply by replacing poor quality foods with food that is high in or fortified with vitamin D. These types of foods tend to be healthier and lower calorie. By replacing the quality of calorie being taken in will lead to weight loss.


With a growing rate of depression and other mood disorders, researchers are beginning to look at vitamin and mineral impacts of mood. Vitamin D receptors have been found on the brain. Furthermore, these receptors are located in areas of the brain that are commonly associated with depression, which alludes to the fact that vitamin D may be able to increase mood and treat or prevent depression. This is a hopeful discovery for individuals dealing with mood and depressive disorders.

D3 that is taken in through sunlight may also enhance mood simply by the method in which it is being taken. People are finding themselves indoors more often and not in the sunlight. Whether it be from a busy schedule, working night shift, or spending prolonged time in front of the television, people are not outside enough. Exposing yourself to sunlight, and D3 vitamin can enhance mood just by changing up your routine.

What Are The D3 Vitamin Deficiency Symptoms

Worldwide, approximately 50 percent of people do not get enough vitamin D. Because of this it is important to take in vitamin D through sunlight, food, or supplementation. The effects of vitamin D deficiency reach beyond fatigue or poor mood as is the result of some vitamin deficiencies. The risks of deficiency of this vitamin should be taken seriously.

Who is at risk?

There are many factors that play into an individual’s risk for vitamin D deficiency. Living in a big city can be a risk. Large buildings blocking sunlight increased pollution, and spending prolonged periods of time indoors may cause someone living in a larger city to become deficient in this vitamin. Having high levels of melanin, the pigment that causes the skin and other areas of the body to be darker than others, will increase the likelihood of vitamin D deficiency. The more melanin in the skin the less vitamin D is able to be absorbed.

Actions that block sun exposure will also increase a person’s risk for vitamin D deficiency. These include sunscreen, extra clothing, umbrellas, and avoiding the sun. Many people will understandably avoid sun exposure at the risk of skin cancer or skin damage. However, those individuals should be careful to take in D3 vitamin through other means.

Age also plays a factor in vitamin D deficiency. As a person ages, their kidneys are less effective at converting D3 vitamin to its active form. People with digestive tract disorders may also be at an increased risk for D3 deficiency due to malabsorption of this vitamin. Cystic fibrosis, chron’s disease, and celiac disease all cause the intestine to not be able to absorb vitamin D from food effectively.

Anyone following a strict vegan diet is putting themselves at risk for a vitamin D deficiency. This is because food sources of this vitamin are mainly animal-based. Therefore, supplementation or exposure to sunlight should be considered.


When vitamin D deficiency is severe osteomalacia may ensue. This is a softening of the bones, unlike osteoporosis which is where the bones become brittle from hormonal changes. Vitamin D assists with calcium and phosphorus absorption which are required to keep the bones strong and avoid this softening. If osteomalacia occurs during important growth stages it can lead to bowing of weight bearing bones.


D3 Vitamin

This is a rare disorder among children from vitamin D deficiency. Rickets is developed the same way that osteomalacia occurs, from an insufficient amount of vitamin D to absorb enough calcium and phosphorus for bone health. While rare, it is a disheartening disorder to observe. Marked by restlessness, pain, slow growth, and physical delays, it is difficult to watch an infant endure such an avoidable disorder.

The Possible D3 Vitamin Side Effects

Vitamin D3 generally has no side effects when it is being taken as directed or at normal doses. However, taking in too much D3 vitamin may lead to nausea and vomiting, decreased apatite and increased thirst, tiredness, mood changes, or increased urination. Toxicity is possible with D3 vitamin due to its fat-soluble nature. Therefore, take D3 vitamin only as directed when taking through supplement form.

An allergic reaction to the D3 vitamin is rare but serious. If rash, swelling, itching, or trouble breathing develops medical attention should be sought immediately.

The Recommended D3 Vitamin Dosage

There are two solubility types of vitamins; water and fat-soluble. D3 vitamin falls into the fat-soluble class. This means that rather than expelling any excess through urine or sweat it is stored in fat. This storage can lead to toxicity in the body. Therefore, proper dosage should be followed.

Dosage for the D3 vitamin is listed in international units (IUs). The standard dosage for children and teens 600 IUs per day. Adults up to age 70 are 600 IUs per day. Age 70 years old and above dosage is 800 IUs per day. Pregnant and breastfeeding women should only have 600 IUs a day.

Because of its fat-soluble nature, it is important to speak with your healthcare provider if you are taking a bile-acid sequestrant or orlistat. Both of these types of medications will alter fat in the body which may impact the effect of vitamin D supplements. It is also important to take a vitamin D supplement with a meal as the fat in the food will aid in its absorption.

D3 Vitamin Highlights

The sunshine vitamin is one of many great sources of vitamin that is essential for many health outcomes in the body. Whether through food, supplements, or sunlight it is important to take in enough, but not more than required, D3 vitamin. If you think you may be at risk for vitamin D deficiency, ask your healthcare provider for a simple blood test called 25- hydroxyvitamin D to check your vitamin D levels.