What is Vitamin D and Why is it Important?

So why do we need sunlight? How little does sunlight help the body? There’s one term that everyone associates with when it comes to sunlight. IT IS VITAMIN D.

The sun’s UV rays are important for your body to produce this nutrient, which is important for your bones, blood cells, and immune system. It also helps you take in and use certain minerals, like calcium and phosphorus.

What is Vitamin D?

One of the most important fat-soluble vitamins, a substance that our body needs to grow, repair bones, and develop normally. It even helps to absorb calcium for our body. Vitamin D synthesizes in the skin and is then metabolized to active metabolite calcitriol in the liver and kidneys. Absorption of calcium is majorly involved in vitamins. Besides dietary intake, cutaneous synthesis is the other and more source of Vitamin D.

Why is Vitamin D important?

It regulates the concentration of calcium and phosphate in the blood that requires the mineralization of bone, muscular contraction, nerve conduction, and general cellular function in all the cells of the body. Vitamin D also supports immune function. Studies show a link between infections like cold, bronchitis, and pneumonia. Low level of vitamin D links with higher levels of inflammation. Vitamin D may be linked to a lower risk of diabetes of type 1 and autoimmune disease. Having enough vitamin D levels may help protect against respiratory illness. A study on COVID 19 patients indicates that enough vitamin D levels decrease the risk of adverse outcomes. Obesity is a risk factor for Vitamin D deficiency. (Vitamin D and Its Potential Benefit for the COVID-19 Pandemic – PubMed (nih.gov)) Your daily need for vitamin D depends on your body size. Adequate vitamin D may help in weight loss, decrease fat and limit weight gain.

Vitamin D exists in two forms: Vitamin D2 and Vitamin D3. The two main forms both play the same role in the body but with slightly different molecular structures.

Vitamin D2 comes from plants, while animals, including people produce D3. Few foods naturally contain vitamin D. Consequently, manufacturers may fortify foods with vitamin D, such as milks, juices, and cereals. Mushrooms are a good natural source of vitamin D2, while fatty fish are good source of vitamin D3. Vitamin D2 is used for rickets, hypoparathyroidism, and familial hypophosphatemia.

Vitamin D3 also called the “sunshine vitamin” processes in our skin when exposed to sunlight especially the UV rays. Since it’s produced in the body Vitamin D3 called as hormone and not a vitamin. Deficiency of this vitamin can lead to osteoporosis, increased bone loss and other cardiovascular diseases.

Vitamin D3 is an essential nutrient in the human diet. It is important for the development and normal functioning of many organs in the body. You should try to get your recommended intake of vitamin D3 from diet and supplements.

People who don’t have gall bladder or digestive problems have reduced levels of Vitamin D3 because it is a fat-soluble vitamin that needs the gall bladder and liver to function for its absorption. D3 has a lot of benefits, of which the main being improving the absorption of calcium and other minerals such as iron, magnesium, zinc, etc. and further regulating its transportation to the bones.

The other benefits are:

• Helps with bone pain
• Lowers blood pressure
• Helps insulin control.
• Prevents cardiovascular diseases
• Helps to reduce cortisol that is your stress hormone.
• Good for patients suffering from asthma

So, it is important to understand the need for Vitamin D3, and if you are getting enough sunlight then no need to supplement on.

Functions of fat-soluble Vitamin D

Vitamin D is important for maintaining the normal function of many non-skeletal tissues like muscles (including heart muscles), immune functions, inflammation, cell proliferation as well as cell differentiation. According to some studies, Vitamin D is also useful as an adjunctive treatment for tuberculosis, psoriasis, many sclerosis, and prevention of certain types of cancers. Vitamin D helps in maintaining plasma calcium concentration and Calcitriol achieves this in 3 ways:

• It increases the absorption of intestinal calcium.
• It reduces calcium excretion by stimulating reabsorption in the distal tubule, and if there is a high concentration of calcium, calcitriol also controls it by reversing the mechanism.
• It deploys the bone mineral.

Calcitriol is involved in insulin secretion, synthesis, and secretion of the thyroid and parathyroid hormones. Calcitriol is again involved in the inhibition of interleukin and antibodies production by T- and B-lymphocytes. It also has a role in the differentiation of monocyte precursor cells and modulating cell differentiation.

Higher Vitamin D status is protective against various cancers including prostate and colorectal cancer, and against prediabetes and metabolic syndrome.

How and when do we make Vitamin D?

Vitamin D is produced in our bodies when we are exposed to the sun. We need vitamin D to help us absorb calcium and phosphate from our diet. Sun and vitamin D are two of the most important contributors to our health. While “soaking up the vitamin D” may sound simple, behind the scenes our bodies are working away at a complex process that turns sunlight into this crucial nutrient. A lack of vitamin D that can cause bone softening can lead to bone deformities. In children, for example, a lack of vitamin D can lead to rickets. In adults, it can lead to osteomalacia, which causes bone pain and tenderness.

Role of Vitamin D in preventing COVID-19

Vitamin D helps in reducing the risk of COVID-19 and helps to acute respiratory tract infections. It includes direct inhibition with viral replication or immunomodulatory ways. The fast-spreading virus is a global health threat with an unstable outcome. Through research and analysis, recent data reported that Vitamin D is a safe supplement and effective against viral and respiratory infections. Although the results from most ongoing randomized clinical trials aiming to prove the benefit of vitamin D supplementation for these purposes are still pending, there is no downside to increasing vitamin D intake. During this global pandemic, people who are at higher risk of Vitamin D deficiency should consider taking Vitamin D supplements and enriched food and have sensible sunlight exposure to maintain serum 25-hydroxyvitamin D at a level of least 30 ng/mL (75 nmol/L) and preferably 40 to 60 ng/mL (100-150 nmol/L).

Food Sources of Vitamin D

Very few foods contain vitamin D:

• Fishes like salmon, tuna, and salmon, are some of the best sources of Omega-3 fatty acids.
• A small amount of vitamin D is present in egg yolks, cheese, and beef liver. So, it is produced in our body itself with the help of sunlight.
• Vitamin D2 which is also known as ergocalciferol, obtained from plant sources (some lichen, fungus, plants like alfalfa, etc.) and is also used in some supplements of vitamin D such as Fortified cereals such as milk, yogurt, orange juice and grains.
• Only food is not enough for the medication of low levels of this vitamin as there aren’t many sources that have a large amount of vitamin D. So, you should turn to vitamin supplements to increase the level of this nutrient with the advice of the doctor.

Deficiency of Vitamin D

Vitamin D deficiency results in low levels of calcium and phosphorus minerals which are essential for bone health. This causes rickets in children and osteoporosis, osteomalacia, and increased fracture risk in adults. The classic disease that is caused by a deficiency of vitamin D is rickets (a bone disorder in children).

Vitamin D deficiency is also correlated to the onset and progression of many chronic diseases like colon, prostate, and breast cancer; cardiovascular diseases; the development of diabetes. Low vitamin D status may increase your risk for Type 1 Diabetes Mellitus, cardiovascular diseases like insulin resistance, hypertension, and brain dysfunctions including depression. So, the deficiency of this fat-soluble vitamin can cause both skeletal as well as non-skeletal diseases. The risk factors for vitamin D deficiency are old age, lack of sun exposure, and dark skin. Its deficiency is common among people living in northern latitudes where sunlight amount varies compared to the rest of the world.

Symptoms of a Vitamin D deficiency

There are various symptoms that lead us to the knowledge of lack of Vitamin in the body such as:

• Depression: Vitamin D is important to produce the feel-good substance serotonin. Many people who seem depressed have a serotonin deficiency.

• Bone pain: Vitamin D is important to process some minerals such as magnesium in the bones. That is why vitamin D deficiency can cause bone problems.

• Muscle weakness: Muscles have vitamin D receptors that need a constant supply of this nutrient. If that does not happen, you can get complaints.

• Respiratory complaints: Complaints to the respiratory system can have many causes, but infections to the lungs can be an expression of a weakened immune system, if they are chronic. A weakened immune system also increases the risk of cancer. You can enjoy the sun without having to completely cover yourself with sunscreen.

• Fatigue: Your body needs enough vitamin D to make energy. If you still feel tired even after a good night, the cause may be a vitamin D deficiency.

• Heart disease: The scientists are still in the dark about the exact link, but there are some studies that make the connection between heart complaints and a vitamin D deficiency.

• Stress: Vitamin D deficiency can cause anxiety and panic, resulting in frequent sweating.

• Bad teeth: Vitamin D is important for the construction and maintenance of the teeth. Even the gums enjoy a good vitamin D status in your body.

• High blood pressure: According to an extensive meta-analysis, it appears that people with low vitamin D values have higher blood pressure.

Treatment

The deficiency of vitamin D can be treated by:

• The consumption of fortified and enriched foods, as well as enough sun exposure (at least 50 minutes per day), should be set for people at risk of vitamin D deficiency.
• If an adequate intake is not achieved, one should take vitamin D supplements, especially during winter months.

Toxicity due to excessive intake

As we know everything in excess leads to toxicity, so we must maintain the level. Some of the ways and reasons are:

• The upper limit of vitamin D intake has been set at 4000 IU per day. Vitamin D intoxication is rare and usually occurs by the excessive and uncontrolled ingestion of supplements or faulty food fortification practices.
• Toxicity occurs due to high plasma and high calcium levels, leading to hypercalcemia. Stopping vitamin D and calcium supplements is mandatory, and one should go through treatment of hypercalcemia.
• Its intoxication can cause excessive bone reabsorption, metastatic calcification, nephrolithiasis, polyuria, CNS, GIT, and CVS symptoms.

Vitamin D has many benefits, it is necessary for many functions in our body. It is essential for the growth and strength of our bones. One of the ways to prevent vitamin D deficiency is to eat foods that have high concentrations of this vitamin, such as milk, fish, and eggs. Vitamin D helps to prevent rickets in children and osteomalacia in adults. Adding more vitamin D-rich meals to your diet will help to prevent flu.