Vitamin D is a staple from childhood. We are all familiar with the stamp on the side of the milk jug that tells us it is fortified with vitamin D and most of us have some sense that vitamin D is good for us.  

But how much thought do we give this ubiquitous nutrient beyond the milk jug? Vitamin D is essential to the health of our bones and teeth. We need vitamin D as part of our daily nutrition. Without a minimum amount of vitamin D, our health suffers.  

What exactly is vitamin D? How do we get vitamin D, and what is the amount of vitamin D we should consume on any given day? What are the sources of vitamin D? What are the consequences of not getting enough vitamin D? This guide will give you all the information you need to understand vitamin D and make sure you include the right foods for sufficient amounts of vitamin D. 

What is Vitamin D?

Vitamin D is a fat-soluble secosteroid that is absorbed through the intestines with the help of calcium, magnesium, and phosphate. 

Often called the sunshine vitamin, vitamin D is produced by the skin in response to sunlight. What we call vitamin D is a class of compounds that includes vitamin D-1, D-2, and D-3. Our bodies naturally produce vitamin D when the skin is exposed to direct sunlight. With the help of the above minerals, we produce enough vitamin D to stay healthy. 

Vitamin D plays a crucial role in several natural functions. It is important for the proper function of the immune system and for the healthy growth of bones and teeth. Vitamin D also helps protect against some specific diseases. 

Vitamin D deficiency leads to some serious problems. These include developmental abnormalities of the bones, soft bones, and fragile bones, or osteoporosis. 

Vitamin D benefits

The fact foods are fortified with vitamin D should make it clear that it is a necessary part of our daily nutrition. Vitamin D is central to maintaining good health as it provides a host of benefits. Some of these benefits include:

Healthy bones 

Vitamin D is crucial to the proper regulation of calcium in the body and maintains the proper level of phosphorus in the blood. These factors are important to healthy bones and bone development.  

Vitamin D allows the intestines to absorb calcium and reclaim calcium from the kidneys. Without vitamin D, calcium would simply be excreted from the body. Calcium is one of the key factors in healthy bones. 

Children who do not get enough vitamin D have bones that develop improperly and will get soft bones, a condition called osteomalacia. In adults, not enough vitamin D results in weak and brittle bones, we know this as osteoporosis.   

Reduces your risk of the flu

A review of several studies showed that vitamin D can reduce your risk of contracting influenza. 

Boosts infant health

The health of infants depends on vitamin D in several ways. For starters, insufficient vitamin D in infants has been linked to high blood pressure. This is due to stiffness in the arterial walls that come from a vitamin D deficiency in infants. 

Other studies have shown that insufficient vitamin D in infants leads to the development of allergies. An increase in allergic sensitivities is linked to a lack of vitamin D. Researchers discovered this link by observing children who live near the equator where they are exposed to massive amounts of sunlight. These children showed almost no signs of allergies and the incidence of epinephrine injections is extremely low. 

Finally, the anti-inflammatory effects of vitamin D have been linked to a lower rate of asthma among children who get proper amounts of vitamin D. 

Pregnancy health

Doctors now know that a lack of vitamin D during pregnancy leads to an increased risk of preeclampsia and premature birth. Preeclampsia is a condition during pregnancy where there is a sudden rise in blood pressure and swelling, mostly in the face, hands, and feet.

Vitamin D deficiency during pregnancy has also been linked to gestational diabetes and bacterial vaginosis in women.  

Fights disease

Most of the primary benefits of vitamin D are well-known. But recent research has linked vitamin D with protection against diseases. Vitamin d has been shown to help resist the development of multiple sclerosis and it helps reduce the chances of childhood flu. 

Fights depression 

Some recent research shows that vitamin D has a positive impact on moods. One study demonstrated that vitamin D fights depressions. Researchers found that people suffering from depression who were given vitamin D supplements showed significant improvements in their symptoms. 

Another study found that people who suffer from anxiety and depression all had a vitamin D deficiency. This suggests that vitamin D is linked to the development of both anxiety and depression. 

Helps you lose weight

If you are trying to lose weight, you may want to consider including a vitamin D supplement in your regimen. There is evidence that vitamin D helps people lose weight. 

A recent study showed that people who are taking calcium and vitamin D supplements experienced a collateral effect of reduced appetite. This helped them lose more weight in less time. 

The fact that vitamin D helps you lose weight has led researchers to link vitamin D with improved heart health and reduced risk of heart disease. 

Sources of Vitamin D

The most common way to get vitamin D is by getting enough sunlight. Vitamin D is produced in the skin by reacting with sunlight. This, of course, require sufficient minerals and other nutrients to work correctly 

There are several foods that are rich in vitamin d. Some of these foods include: 

• fatty fish, such as salmon, mackerel, and tuna
• egg yolks
• cheese
• beef liver
• mushrooms
• fortified milk
• fortified cereals and juices 

Again, the best way to get enough vitamin D is by being out in the sun. Simply by spending some time in the sun our bodies can produce all the vitamin d we need in a day. Some tips for getting vitamin D from sunlight include:

• 15 minutes for a person with light skin
• a couple of hours for a person with dark skin

Very few foods contain significant amounts of vitamin D, so people can ensure they get enough of the vitamin by scheduling regular time outdoors.

When the sun’s ultraviolet B (UVB) rays hit a person’s skin, processes inside the tissue start making vitamin D for the body to use. It is essential to remember, however, that too much sun exposure can burn the skin and potentially lead to skin cancer.

Vitamin D helps the body to absorb calcium, which is one of the main building blocks of bone. The body also needs vitamin D to keep the nerves, muscles, and immune system working properly.

Deficiency of Vitamin D

Vitamin D deficiency is a serious problem. Though not as prevalent in western countries as it once was, vitamin d deficiency still occurs for a variety of reasons. 

Some of the common causes of vitamin D deficiency can include:

Skin type: Darker skin and the overuse of sunscreen can reduce the body’s ability to absorb the ultraviolet radiation B rays that are necessary to produce vitamin D. 

Sunscreen: Sunscreen with an SPF factor of 30 or higher will inhibit your body's ability to properly absorb sunlight for the production of vitamin D. Some sunscreens can inhibit the absorption of ultraviolet B rays by as much as 95 percent.  

Geographical location: People who live in northern regions or areas with high pollution levels can suffer from vitamin D deficiency from lack of sunlight. People who work night shifts and those who are homebound can also suffer from this problem. 

Breastfeeding: Children who are exclusively breastfed should get some kind of vitamin D supplement. The American Academy of Pediatrics recommends that breastfed infants receive 400 IU per day of oral vitamin D. 

We can always make up for a lack of sunlight and vitamin D by taking a vitamin D supplement. However, doctors recommend that we get our vitamin D through natural sources since these are the most readily usable by the human body. 

Symptoms of vitamin D deficiency range from mild to severe. Some of the common symptoms of vitamin D deficiency include:

• regular sickness or infection
• fatigue
• bone and back pain
• low mood
• impaired wound healing
• hair loss
• muscle pain

Long term vitamin D deficiency can lead to some severe illnesses. These illnesses include:

• cardiovascular conditions
• autoimmune problems
• neurological diseases
• infections
• pregnancy complications
• certain cancers, especially breast, prostate, and colon.

The good news is that it is now easy to get all the vitamin D you need. Even those who are at risk for vitamin D deficiency can get vitamin D from natural and fortified food sources, as well as supplements. 

Vitamin D dosage

Vitamin D is generally measured in micrograms or international units (IU). One microgram is equal to 40 IU. The recommended dosage of vitamin D is relative to age. 

People can measure vitamin D intake in micrograms (mcg) or international units (IU). One microgram of vitamin D is equal to 40 IU.

• Infants 0–12 months: 400 IU (10 mcg).
• Children 1–18 years: 600 IU (15 mcg).
• Adults up to 70 years: 600 IU (15 mcg).
• Adults over 70 years: 800 IU (20 mcg).
• Pregnant or lactating women: 600 IU (15 mcg).

You can generally get enough vitamin D from sunlight by exposing your skin to the sun for about 5-10 minutes a day, 2-3 times a week. Vitamin D breaks down quickly and needs to be replenished regularly. Take extra care to get vitamin D during winter months when sunlight is diminished. 

Side effects of Vitamin D 

The only issue with vitamin D is getting too much of it. The upper limit of how much vitamin D you should get in a day is 4000 IU. Beyond this, there are a few side effects to take note of. These include:

• loss of appetite
• dry mouth
• a metallic taste
• vomiting
• constipation
• diarrhea

Again, you should be able to get all the vitamin D you need from sunlight. If you take a vitamin D supplement, just be aware of how much you are taking at any given time and adjust accordingly. 

Vitamin D FAQs

What is vitamin D? 

Vitamin D is a fat-soluble secosteroid that is absorbed through the intestines with the help of calcium, magnesium, and phosphate. 

How do we get vitamin D? 

The most common way to get vitamin D is by getting enough sunlight. Vitamin D is produced in the skin by reacting with sunlight.

What food contains vitamin D? 

Fatty fish, such as salmon, mackerel, and tuna, egg yolks, cheese, beef liver, mushrooms, fortified milk, and fortified cereals and juices. 

What are the benefits of vitamin D? 

Vitamin D builds healthy bones and teeth. It can help fight disease, reduce depression, and help you lose weight. 

Conclusion

Common vitamin D, the vitamin we have seen on milk cartons all our lives, is a powerful and essential nutrient for building healthy bones and teeth. It can help us lose weight and fight depression and anxiety. This common nutrient has more to it than most of us are aware of. 

Perhaps one of the most surprising things about vitamin D is that we make it ourselves by being in the sun. simply by spending time in the sun, our bodies, with the help of some key nutrients, make vitamin D on its own. 

There are also some serious consequences to not getting enough vitamin D. Soft and brittle bones are the results of a vitamin D deficiency. Thankfully, this is rare these days thanks to vitamin D fortified foods and a greater awareness of nutrition in general. 

There are some great vitamin D supplements for people who struggle to get the recommended amount of vitamin D and for people with extra needs like older people. The important thing to remember is that vitamin D is essential. Get some sun and stay healthy.