Vitamin D: Functions And Benefits

One of the essential fat-soluble vitamins is Vitamin D. It is also referred as sunshine vitamin as sunlight is a natural source of vitamin D. It exists in mainly two forms:

Vitamin D2: This is also known as Ergocalciferol. It is obtained through normal dietary intake.
Vitamin D3: This is also known as Cholecalciferol. It is produced in the body, naturally.

Vitamin D is very important for maintaining bone’s health and remodeling.

Functions

Vitamin D performs different functions in the body. This includes,

Promotes healthy bones and teeth
Regulates cardiovascular health
Regulates insulin levels and helps in diabetes management
Controls lung infection
Maintains health of the brain and nervous system
Controls expression of certain genes involved in cancer development.

Here is the description about the important roles of Vitamin D:

Promotes healthy bones

Vitamin D regulates calcium and phosphorus levels in the blood. As these minerals are necessary for controlling bone metabolism, therefore it keeps the bone strong. Lack of adequate levels of Vitamin D can cause rickets in children and osteomalacia in adults. These can result in muscle weakness, poor bone density and softened bone.

Among post-menopausal women, lack of Vitamin D can cause osteoporosis which results in brittle bones and frequent fractures.

Therefore, vitamin D should be maintained at adequate levels to regulate healthy bone status.

Protection against virus infection

A study reported that vitamin D provides immunity against influenza virus. It has also showed beneficial outcomes against coronavirus.

Vitamin D acts as a modulator of the immune system. It provides effective physical barrier and strengthens the immunity against upper respiratory tract infections. In a recent study, it was reported that prophylactic supplementation of vitamin D (in doses up to 2000 IU/d) helped to decrease the severity of COVID-19 infection, mainly in elderly population. It has demonstrated antiviral and anti-inflammatory actions.

Role in pregnancy

Women who have vitamin D deficiency during pregnancy have a higher risk of preeclampsia and to give birth to premature babies. During pregnancy, Vitamin D has also been associated with greater risk of gestational diabetes and bacterial vaginosis.

Dietary Sources

Mushroom is a rich source of vitamin D. Other important sources includes almond milk, cow’s milk, orange juice, oatmeal, soy milk, nuts. Egg yolk, cod liver oil, salmon, herring, tuna are few of the animal sources that provide excellent source of vitamin D.

Recommended dosage (RDA)

RDA, for vitamin D is 600 international units (IU) or 15 mcg per day for young adults and 800 IU (20 mcg) per day for adults older than 70. One microgram of vitamin D is equal to 40 IU.

Deficiency

Deficiency of vitamin D can occur due to several reasons:

People who stay in areas that are highly polluted, are homebound or work during night shifts generally do not get sufficient amount of sun exposure. People with dark skin tone have reduced ability to absorb ultraviolet radiation B (UVB) rays from the sun. Application of too much sunscreen with a sun protection factor (SPF) of 30 can also reduce Vitamin D synthesis.

Infants who are breastfeeding require 400 international units (IU) per day of oral vitamin D, especially if they are minimally exposed to sun.

Signs and Symptoms

Individuals with vitamin D deficiency can have the following symptoms:
Bone pain
Muscle pain and weakness
Fatigue
Shift in moods
Increased risk of infections
Wound healing impairment
Brittle bone

Vitamin D deficiency for a prolonged time period can cause major complications such as:

Pregnancy associated problems
Cardiovascular conditions
Increased cancers of the breast, prostate, and colon
Frequent Infections
Neurological diseases

Overview

Vitamin D is an essential fat soluble vitamin. It maintains bone metabolism, improves immunity and provides protection against cardiovascular, nervous and pregnancy associated problem. Synthesis of sufficient amount of Vitamin D depends on sun exposure, therefore its level should be maintained by supplements in order to meet its demand