VITAMIN D- THE 'SUNSHINE' VITAMIN

It is also known as 'Cholecalciferol' or 'Calcitriol'. Cholecalciferol or Calcitriol is a fat soluble vitamin and is produced in the body with the help of skin, liver and kidneys mainly.

Nearly 76% of Indian population suffer from vitamin D deficiency.

About 90% of the required Vitamin D is synthesized in the skin under sun exposure. Hence, also called as the 'sunshine vitamin'.

How is it formed?

An inactive form called 7-dehydrocholesterol is present in skin layers which in the presence of UV light is absorbed into the bloodstream. Then, it reaches the liver and then the kidneys to form the active form of vitamin D known as 1, 25 dihydroxycholecalciferol or calcitriol. This calcitriol plays a very important role in calcium metabolism.

Types of vitamin D:

From where can we get Vitamin D?

How much vitamin D is required?

Category	Age	RDA (Recommended Daily Allowances)
Infants	0-12 months	10 mcg (400 IU)
Children	1-13 years	15 mcg (600 IU)
Adolescents	14-18 years	15 mcg (600 IU)
Adults	19-70 years	15 mcg (600 IU)
Old adults	> 70 years	20 mcg (800 IU)
Pregnant and lactating females	14-50 years	15 mcg (600 IU)

IU= International Unit

How much levels of vitamin D are needed by the body?

nmol/L	ng/L	Health status
<30	<12	Associated with vitamin D deficiency, which can lead to rickets in infants and children and osteomalacia in adults
30 to <50	12 to <20	Generally considered inadequate for bone and overall health in healthy individuals
≥50	≥20	Generally considered adequate for bone and overall health in healthy individuals
>125	>50	Linked to potential adverse effects, particularly at >150 nmol/L (>60 ng/mL)

Who is at risk of Vitamin D deficiency?

1. Breastfed infants- as human milk is a poor source of vitamin D.

2. Old adults- the absorption of vitamin D by skin is affected as age progresses.

3. People with dark skin have less ability to produce vitamin D via skin due to high amount of melanin.

4. Intestinal disorders like Crohn's disease or celiac disease.

5. People with obesity- due to high amount of fat content, vitamin D is dissolved in the fat as it is fat soluble.

6. Disorders like hyperparathyroidism (overactive parathyroid gland), TB, sarcoidosis, lymphomas (cancer), malabsorption syndromes, etc.

7. People who take medicines that affect vitamin D metabolism, such as cholestyramine (a cholesterol drug), anti-seizure drugs, glucocorticoids, antifungal drugs, and HIV/AIDS medicines.

8. People who live in areas where sunlight doesn't reach.

9. People practising burqah or purdah system.

10. People using excessive sunscreen lotions, as it blocks the absorption of vitamin D.

Role of vitamin D in the body:

Signs and symptoms:

Treatments: