What Is Vitamin D?
Vitamin D is extremely important for good health and for strong bones. Vitamin D is also very important to ensure that one’s heart, muscles, lungs and brain function properly. This vitamin also is critical in the body’s ability to fight infection.
The human body can produce vitamin D from the sun, and it also can be obtained from nutritional supplements and from some foods.
The vitamin D that is produced when sunlight hits the skin, as well as that from supplements, must be transformed by the body several times before it can be property utilized for essential bodily functions. Once the vitamin D is ready for use, the body uses it to manage how much calcium is in the blood, gut and bones, and to help the cells of the body to communicate.
What Does Vitamin D Do?
The links between vitamin D and strong bones was made decades ago, when scientists observed that sunlight – which helps the body to produce vitamin D – can prevent rickets in children. Today, vitamin D is recognized as an essential part of good health, and it not just for bones. It is very important to prevent many serious, long term health problems.
As noted earlier, vitamin D is important for strong bones, and calcium and phosphorus are as well. Vitamin D is needed to properly absorb these minerals. Even when a person eats foods with high levels of phosphorus and calcium, without sufficient vitamin D, you will not be able to fully absorb them into the body.
Essential functions of vitamin D in the human body are:
- Helping the immune system to properly function
- Proper muscle function
- Efficient cardiovascular function
- Healthy lungs and airways
- Good brain development and function
- Fighting cancer-causing molecules in the body
When the body gets the vitamin D that it needs, it is actually transformed into a hormone, which is known as both activated vitamin D and also calcitriol.
It is recommended that most adults get 600 IU of vitamin D per day.
What Are the Effects of a Lack of Vitamin D?
If the body lacks vitamin D, this is known as vitamin D deficiency. Severe deficiency of this vitamin can cause bone damage in children and adults. In children this is called rickets, and in adults it is known as osteomalacia. Both conditions lead to thin, brittle and soft bones.
Lack of vitamin D also has been linked to asthma, cancer, type II diabetes, hypertension, depression, Alzheimer’s and multiple sclerosis.
Some signs that you could have vitamin D deficiency or are more susceptible to it:
- Darker skin: African Americans and others with dark skin have a higher risk of being deficient in this vitamin; if you have darker skin, you need much more sun exposure to produce the same amount as someone who has white skin.
- Feeling depressed: Serotonin, which is the brain hormone that is related to an elevated mood, increases when you are exposed to sunlight and falls without it. People with lower levels of vitamin D are much more likely to be depressed.
- More than 50 years old: As you age, your skin does not make as much vitamin D when exposed to the sun. Your kidneys also decrease in efficiency, which means your body converts less vitamin D into a usable form.
- Obesity: Vitamin D is fat soluble, which means that the body collects it and you will need higher levels of it if you are overweight.
- Head sweats: A classic sign of this vitamin deficiency is having a sweaty head when you are inactive.
New research also suggests that low levels of vitamin D could be linked to symptoms of dry eye.
How Vitamin D Works
Vitamin D mostly comes from the skin when it is exposed to sunlight. After this occurs, the body uses several chemical processes to transform it into a usable form. When the skin is exposed to sunlight, it makes the vitamin and sends it to the liver. It also is sent to the liver when a person eats foods with vitamin D, or takes nutritional supplements.
What Are Sources of Vitamin D?
Some of the sources of vitamin D include these:
- Sunlight. You should get about 20 minutes of sun exposure to get the vitamin D that you need, although you may need more at higher latitudes.
- Fatty fish. Best fish for vitamin D include salmon, trout, tuna and mackerel.
- Canned tuna fish. This is a good option because it is less expensive than fresh fish and has a long shelf life.
- Fortified milk: Most milk in the US has vitamin D added, but note that ice cream and cheese do not.
- Egg yolks: This is one of the most affordable ways to get fresh vitamin D every day, but only the yolk contains the vitamin, not the white.
- Beef liver: While not as popular as other foods containing vitamin D, one three ounce serving has 50 IU of this vitamin.
Pork, caviar, many fortified cereals and tofu also contain vitamin D.
20 Reasons to Supplement with Vitamin D
Many Americans do not get enough vitamins, including vitamin D, from their diets. That is why more than half of Americans take at least one supplement per day. Some of the best reasons that you should take vitamin supplements containing vitamin D and other vitamins:
- Getting enough vitamin D from sunlight or diet alone can be difficult for many people. By taking a vitamin D supplement, you know that your body is getting what it needs to carry out essential functions.
- Getting all of the vitamins that you need from one’s diet every day can be difficult because you need to eat so many types of foods.
- Many of the foods that Americans eat every day, such as many convenience and packaged foods, do not contain enough vitamins for optimal health.
- Supplementation with vitamin D can avoid serious health complications in children and adults, such as weak and brittle bones.
- Vitamin D supplementation can help to prevent cold and flu, according to some studies.
- Supplementation with vitamin D can improve the health of infants; a study showed that infants given 2000 IU of the vitamin per day had less arterial wall stiffness after 16 weeks.
- Breastfed infants can benefit from vitamin D supplementation because human milk contains little of the vitamin. These infants should get 400 IU of vitamin D each day.
- Vegetarians and vegans often do not get the vitamins they need from their diet, especially vitamin D. These people also may not get enough iron, magnesium, selenium, zinc and calcium.
- Senior citizens tend to absorb vitamins less efficiently than the young, so a vitamin D supplement can improve health.
- People with Crohn’s disease or celiac disease can benefit from supplementing with vitamin D.
- Vitamin D, calcium and phosphorus are essential to healthy bones, and this is especially important in the elderly years. Taking a supplement can prevent fractures and osteoporosis.
- Supplementing with vitamin D can prevent tooth decay and diabetes.
- Vitamin D supplementation can reduce your risk of multiple sclerosis, according to the Journal of the American Medical Assn.
- Supplementation with vitamin D can reduce heart disease risk. It is thought that supplementation can reduce blood pressure, boost vascular performance and also improve glycemic control.
- Vitamin D supplements can reduce your chances of getting the flu.
- Supplementing with vitamin D can reduce your risk of type 2 diabetes.
- Some experts believe that supplementing with vitamin D can reduce your risk of colon cancer.
- Vitamin D supplementation can elevate the mood, as it has a positive effect on serotonin levels.
- 77% of Americans are deficient in vitamin D, so, supplementing can definitely help.
- Higher levels of vitamin D can help to burn fat; there are special receptors for vitamin D in the body that signal whether to burn fat cells or store them.
Of course, getting too much of any vitamin is not a good thing. If you supplement with too much vitamin D, you can get something called vitamin D toxicity. This can occur if you take 40,000 IU of vitamin D for long periods of time.
Remember that vitamin D is fat soluble, so it will take a while for your body to get rid of excess vitamin D.
Side effects and symptoms of excessive vitamin D are:
- Lack of appetite
- Abdominal pain
- Muscle weakness and/or pain
- Pain in bones
A blood test can be done by your doctor to determine if you have vitamin D toxicity; he or she will measure your level of 25(OH)D to see if your vitamin D level is too high.