Importance of Vitamin D: Everything That Makes It Pivotal for Your Health

Vitamin D, also known as the sunshine vitamin, is one of the most important nutrients required by the body for its optimal functioning. The body produces it as a response to sun exposure. However, Vitamin D is also present in certain foods and can be consumed through supplements. Its primary role lies in keeping bones and teeth healthy. But the importance of vitamin D goes far beyond the basics. Read through to know the different Vitamin D uses in the human body.

What is Vitamin D?

Despite its name, vitamin D is technically not a vitamin. It is a hormone secreted by the skin layers as a response to sun exposure. The liver and kidneys then synthesise vitamin D produced in the skin into an active hormone through the process of hydroxylation. This is then used by the body for a range of functions.

Vitamin D includes:

1. Calcidiol (25-hydroxyvitamin D)
2. Calcitriol (or 1,25-dihydroxyvitamin D)
3. Ergocalciferol (vitamin D2)
4. Cholecalciferol (vitamin D3)

When consumed through food, it is a fat-soluble vitamin that is synthesised with the help of dietary fats. [vitamin D has two main forms, D₂ (ergocalciferol) and D₃ (cholecalciferol) that comes through food/dietary supplements]

How are Vitamin D Levels Controlled?

Vitamin D is important for the absorption of calcium and phosphorus. As the levels of calcium fall in the bloodstream, the parathyroid glands increase the activity of the enzymes that are responsible for the production of vitamin D. The skin, on exposure to sunlight, begins to produce Vitamin D, which enhances calcium absorption and pushes it back to optimal levels. Once the normal calcium levels are restored, the vitamin D sends signals to the parathyroid glands to halt the release of parathyroid hormone.

Importance of Vitamin D

Getting enough Vitamin D is important for the healthy growth and development of the body. The Vitamin D benefits include:

1. Healthy Bones and Teeth

Vitamin D is vital for intestinal calcium and phosphorus absorption. Adequate levels of the minerals are important for healthy bone mineralization which is important for healthy bones and teeth. Low levels of Vitamin D directly affect the calcium levels in the body, leading to the early onset of osteoarthritis, osteoporosis, and tooth loss.

2. Promotes Skeletal Muscle Regeneration

Optimum levels of Vitamin D in the body are associated with increased muscle strength. Vitamin D is crucial for the maintenance of skeletal muscles. It promotes mitochondrial health, reduces injury rates, and improves sports performance. While 99% of the body’s calcium is stored in bones, the remaining 1% is found in blood, muscles, and tissues. Therefore, adequate vitamin D levels increase calcium absorption, promoting muscle health.

3. Boosts Immune System

One of the most important Vitamin D benefits is its role in strengthening the immune system. Vitamin D is responsible for stimulating the production of T-cells. The T-cells are a part of the immune system and grow from the stem cells in the bone marrow. These cells promote a protective response to disease-causing pathogens, including viruses, bacteria, and fungus. Adequate intake of Vitamin D is also associated with a reduced risk of developing autoimmune diseases by boosting immune function.

4. Prevents Certain Types of Cancer

Research suggests that there is a possible link between Vitamin D and the development of cancers. Vitamin D supports the repair and regeneration of cells, which thwarts the growth of cancerous tumours. It also stimulates the death of cancer cells and inhibits the formation of blood vessels in tumours which feed the cells, thus pushing them to death.

5. Improves Cognitive Functioning

An adequate level of Vitamin D is paramount for numerous functions in the body, including optimal brain functioning. The Vitamin D receptors are spread across the brain and the spinal cord. Vitamin D benefits you by activating and deactivating the synthesis of neurotransmitters. It also supports nerve growth and repair. Studies show that Vitamin D helps protect the neurons and plays an important role in reducing inflammation within the brain. 

6. Helps Uplift Mood and Reduce Depression Symptoms

Vitamin D plays an important role in regulating mood and decreasing the risk of depression. As Vitamin D is the sunshine vitamin, its low levels are particularly linked to the development of Seasonal Affective Disorder (SAD). Vitamin D levels also regulate the levels of serotonin, the hormone responsible for regulating mood. No wonder sitting in the sun uplifts the mood automatically.

7. Promotes Weight Loss

Did you know Vitamin D benefits you by helping you get your weight right? Research shows that people trying to shed a few kilos can do so only if their Vitamin D levels are adequate. On the other hand, people with vitamin D deficiency are more likely to be overweight and obese. This is because Vitamin D plays an important role in keeping body fat levels down.

8. Helps Lower Blood Pressure

Vitamin D plays an important role in regulating blood pressure. Research shows that Vitamin D supplements help reduce both systolic and diastolic blood pressure levels in patients with essential hypertension. 

9. Promotes Heart Health 

Vitamin D benefits the heart by lowering blood pressure. It also improves cardiovascular health by inhibiting the hormones that increase the constriction of blood vessels. Vitamin D reduces inflammation, a condition leading to the hardening of the arteries.

10. Reduces the Risk of Type 2 Diabetes

The cells in the pancreas are responsible for secreting insulin, which drives the body’s tolerance to glucose and resistance to insulin. Vitamin D deficiency reduces the secretion of insulin from the pancreas. This is linked to a higher risk of developing Type 2 Diabetes.

Reasons for Vitamin D Deficiency

Although the body produces enough Vitamin D to cater to its needs, some people are more likely to develop Vitamin D deficiency. The factors that influence this include:

1. Colour of Skin – Dark-coloured skin has higher skin pigmentation, inhibiting the body’s ability to absorb ultraviolet B rays from the sun. Exposure to UVB rays helps the skin produce Vitamin D.
2. Use of Sunscreen Lotions – The use of sunscreens is widely propagated to reduce exposure to harmful UV rays. This also cuts down the skin’s ability to produce vitamin D.
3. Insufficient Sun Exposure – To maintain healthy levels of Vitamin D in the blood, 10-30 minutes of exposure to midday sun is required. Lack of sun exposure increases Vitamin D deficiency.
4. Breastfeeding Infants – Breastfed infants are more likely to be Vitamin D deficient.
5. Elderly People – The skin’s ability to synthesise Vitamin D reduces with age. Also, debilitating conditions may make them homebound. This leads to Vitamin D deficiency.
6. Obese and Overweight People – High levels of body fat restrict the body’s ability to absorb vitamin D from the skin. This leads to Vitamin D deficiency.
7. Medical Condition That Limits Fat Absorption – People suffering from conditions like liver disease, cystic fibrosis, celiac disease, etc. suffer from fat malabsorption. Thus, they tend to develop Vitamin D deficiency as Vitamin D is a fat-soluble vitamin. Its absorption in the gut depends upon the body’s ability to absorb dietary fats.
8. People Operated For Gastric Bypass Surgery – People who undergo gastric bypass surgery have a portion of their large intestines removed. This also restricts their fat absorption ability which affects Vitamin D levels in the body.

Recommended Intake of Vitamin D

The recommended daily dietary intake of Vitamin D is as follows:

0-12 months – 10 mcg

1 – 50 years – 15 mcg

51 – 70 years – 15 mcg

Above 70 years – 20 mcg

Sources of Vitamin D

Vitamin D can be sourced through food and supplements.

1. Food Sources

Animal-based foods like beef, pork, chicken, turkey, and eggs are typically rich in Vitamin D. Soy, almonds and oat milk are preferred by vegetarians to boost their vitamin D levels. Dairy products are usually fortified with Vitamin D.

2. Dietary Supplements

Dietary supplements are an effective way to make up for Vitamin D levels. Vitamin D supplement benefits as it contains both Ergocalciferol (vitamin D2) and Cholecalciferol (vitamin D3). These are well absorbed in the gut, cutting down Vitamin D deficiency effectively and quickly.

Conclusion

The importance of Vitamin D is well pronounced in every function of the body. Its role extends beyond the primary function of maintaining healthy bones and teeth. Research suggests that Vitamin D benefits the body in innumerable ways, including regeneration of skeletal muscle, boosting immunity, aiding weight management, and preventing the risk of developing cancers, heart ailments, and type 2 diabetes. 

Although the vitamin is prepared naturally within the body on exposure to the midday sun, it can also be sourced through food and dietary supplements in people who fail to produce the required levels. 

While infants require a daily dose of 10 mcg of Vitamin D, the dose increases to 15 mcg for ages up to 70 years. People above 70 years of age must have 20 mcg of Vitamin D in their daily diet. Being a fat-soluble vitamin, an overdose of Vitamin D can lead to Vitamin D toxicity. Therefore, it is important to be careful about accidental overconsumption and avoid prescription errors.