We have all heard of vitamin D and how staying indoors for extended periods can cause you not to get enough of it; but how exactly does sunlight lead to our body producing a vitamin that’s vital to our health? And, what role does vitamin D play in our bodies, and just how vital is it to functions like bone strength and immunity? Well, vitamin D is incredibly important for a variety of reasons; and you might even have a vitamin D deficiency without even knowing it.
Vitamin D Overview
Vitamin D is a fat-soluble vitamin, which is different from water-soluble vitamins like vitamin C. Being fat-soluble, vitamin D is actually dissolved in the fats and oils in your body, meaning it can be stored for a long time. There are two main types of vitamin D: vitamin D3 and vitamin D2.
What Is Calciferol?
Calciferol is the chemical name for vitamin D. The chemical name for vitamin D2 is ergocalciferol. For vitamin D3, the chemical name is cholecalciferol. When vitamin D is being synthesized, calciferol goes several chemical changes in the body for it to be used by our cells.
What Causes Vitamin D Deficiency?
There are several risk factors that can lead to vitamin D deficiency. Most of them involve not getting enough sunlight because we get a large amount of our natural vitamin D from what our body produces when exposed to the sun. If you live in an area with high pollution, or a big city where buildings can block the sunlight, you may have a higher risk of vitamin D deficiency. Also, spending more time indoors and using sunscreen can prevent your exposure to the sun, putting you at risk of a deficiency in vitamin D.
Another risk factor for vitamin D deficiency that you may not expect is having darker skin. This is because higher levels of melanin allow less vitamin D to be absorbed into the skin.
Vitamin D Deficiency Symptoms
Having vitamin D deficiency is fairly common; about 1 billion people in the world suffer from it, including 41.6% of US adults according to a 2011 study. The symptoms of vitamin D deficiency can often be subtle, so most people don’t even realize that they’re deficient. The most common symptoms of vitamin D deficiency are:
- Having a weakened immune system
- Feeling tired and fatigued
- Pain in the bones and back
- Slow healing of wounds
- Low bone mineral density
- Hair loss
- Chronic muscle pain
- Stress fractures
Additionally, studies have shown that individuals with low vitamin D levels have a much higher chance of having heart disease, diabetes 1 and 2, dementia, autoimmune diseases, and cancer. Research has also linked vitamin D deficiency to a reduced life expectancy. So, we need not say that getting the right amount of vitamin D is important. But, precisely what does vitamin D do?
What Does Vitamin D Do?
In order to become active in the body after being absorbed, vitamin D must first be converted into calcidiol in your liver, which is its storage form. Then, it’s turned into calcitriol in your kidneys, which is its active steroid-hormone form. As calcitriol, it interacts with the vitamin D receptor found in almost every cell in your body. The way it changes cells and makes a difference in the body is by turning genes on and off, like most other steroidal hormones.
One of the primary things that vitamin D is able to do in the body is to affect various cells related to bone health. It does this by promoting the absorption of calcium and phosphorous that come from your gut, encouraging stronger bones. However, calcium production isn’t the only thing it helps with; new research shows that vitamin D may also help with immune function and protection against cancer.
Sources of Vitamin D
There are a variety of natural sources in which you can get vitamin D. The first thing that comes to mind is sunshine, which is actually one of the best natural ways to get vitamin D. When your skin is exposed to the UVB rays from the sun, the cholesterol in your skin produces vitamin D. In order to get substantial amounts of vitamin D to garner benefits from the sunshine, you’ll need to expose a large part of your body.
However, sunshine isn’t the only way for you to get vitamin D. There’s a long list of food sources that are chock full of vitamin D that you should include in your diet especially if you feel that you need more in your body. You can get vitamin D through diet by eating:
- Cod liver oil
- Fish, such as salmon, tuna, and sardines
- Beef liver
- Egg yolks
- Shellfish, such as shrimp
- Foods fortified with vitamin D, including fortified milk, cereal, yogurt, and orange juice
Vitamin D Supplements
If you feel that you may be deficient in vitamin D and you need much more significant amounts than you can get with safe sun exposure and diet, then you may want to consider taking a vitamin D supplement. We recommend the NatureWise Vitamin D3 2,000 IU softgel because it contains a safe and healthy amount of vitamin D3 to take daily for stronger bones, muscles, and immune system.
However, if you are deficient in vitamin D, you may need to take a higher dose. In this case, we recommend the NatureWise Vitamin D3 5,000 IU softgels because it has a stronger dosage to help bring you back to normal vitamin D levels. While it is above the recommended daily safe intake of 4,000 IU, it’s not close at all to a dangerous level. The high dosage may be required for you if you suffer from a deficiency, but be sure to discuss with your doctor.
Benefits of Vitamin D
Vitamin D can do more for our bodies than its basic chemical functions. There are several real benefits that you could potentially garner from getting a healthy amount of vitamin D in your body.
Helps Fight Diseases
There have been several studies showing that vitamin D may be effective in boosting your immune system and helping to fight various diseases. In 2010, research showed that vitamin D could also help to reduce the likelihood of developing the flu. One 2006 study showed that vitamin D was able to reduce the risk of developing multiple sclerosis. Further findings in 2008 found that vitamin D may actually be able to decrease your chance of developing heart disease. One study even linked 2,000 IU of vitamin D per day to a 78% reduced risk of type 1 diabetes.
Vitamin D and Depression
Several studies have looked into the effect that vitamin D can have on depression. One study showed that people with depression who took vitamin D supplements were able to notice an improvement in their symptoms. Another study found that vitamin D deficiency was actually more common in those who were also experiencing anxiety and depression.
Helps Weight Loss
This one may be surprising, but vitamin D has been shown to boost weight loss. One study found that people who took daily calcium and vitamin D supplements were able to lose more weight than those who took a placebo. The reason behind this was the appetite-suppressing effect that the supplements had on the individuals in the study; the supplements made them less hungry, so they ate less and lost weight.
Stronger Bones and Muscles
We know that vitamin D has a strong ability to help assist in the maintenance of bone strength. However, research has shown that higher doses of vitamin D can actually help prevent osteoporosis and fractures from falling in older adults. Vitamin D has also shown promise in assisting physical strength, with research finding that it helps in both upper and lower limbs.
Can You Take Too Much Vitamin D?
Like most vitamins, there is such a thing as “too much of a good thing.” The normal blood serum levels of vitamin D typically range from 50 to 100 micrograms per deciliter. Generally, the recommended IU per day for children, teens, and adults up to age 70 is 600 IU. When it comes to adults over the age of 70, the amount increases to 800 IU because the elderly are more likely to be deficient in vitamin D.
According to the US National Academy of Medicine, the safe daily intake of vitamin D is 4,000 IU. Anything more than that may be dangerous to the body and lead to vitamin D toxicity.
Vitamin D Toxicity
Also called hypervitaminosis, vitamin D toxicity is a very rare condition. However, unlike vitamins like vitamin C, it’s fat-soluble instead of water-soluble. This means that the body has no easy way of getting rid of it, so an excessive amount of vitamin D can actually build up inside the body.
People with symptoms of vitamin D toxicity usually have levels above 150 ng/mL in the body. This is generally caused by an excessive dose of vitamin D supplements because it’s relatively difficult to get excess vitamin D from diet and sunshine alone.
Research has shown that a daily intake ranging from 40,000 to 100,000 IU for one to several months can cause vitamin D toxicity in humans. This condition is usually reversible, but severe cases of vitamin D toxicity can eventually cause kidney failure and calcification of the arteries if gone unchecked.
Vitamin D Side Effects
One of the most common side effects linked to vitamin D toxicity is hypercalcemia, which is characterized by a buildup of calcium in the blood. Nausea, vomiting, diarrhea, constipation, and weakness are all early symptoms of hypercalcemia. Further down the line, you may experience excessive thirst, an altered state of consciousness, high blood pressure, kidney failure and kidney tube calcification, and hearing loss. It usually takes a few months to resolve hypercalcemia because of how slowly it’s released into the body, due to it being stored in the body’s fat.
While vitamin D is important for proper calcium absorption and bone metabolism in order to maintain strong bones, having too much may actually have the opposite effect. Contrary to most symptoms of vitamin D toxicity, bone loss is a symptom that may happen due to large doses leading to low levels of the vitamin K2 in the blood. This is because vitamin K2 is vital for keeping calcium in the bones and out of the blood; research has shown that very high vitamin D levels may reduce the activity of vitamin K2.
Difference Between Vitamin D and D3
Vitamin D2 (chemically known as ergocalciferol) can be found in the following food sources:
- Mushrooms grown in UV light
- Fortified foods
- Dietary supplements
Vitamin D2 is much cheaper to produce that vitamin D3 because it comes from plant-sourced foods, making it the much more commonly found form in fortified foods. Similar to how sunlight on the skin creates vitamin D3, UVB light exposed to plants and mushrooms forms vitamin D2.
Vitamin D3, with the chemical name cholecalciferol, differs from vitamin D2 because of its food sources. You can mainly find vitamin D3 in:
- Oily fish
- Egg yolks
- Dietary supplements
When your skin is exposed to sunlight, the type of vitamin D that is made is vitamin D3. When it comes to effectiveness, vitamin D3 may actually be more effective at boosting the vitamin D levels in your body. This is because vitamin D3 when metabolized in the liver, is able to yield much more of the main circulating form of vitamin D (called calcifediol). One study found that a single dose of vitamin D was almost twice as effective as vitamin D2 in raising levels of calcifediol.