Vitamin D3: Benefits, Sources, Deficiency, and More 

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Vitamin D3 

An NCBI article titled ‘Cholecalciferol’ Vitamin D3 also referred to as cholecalciferol, is produced in the skin and can also be found in some foods like eggs, dairy and fish. 

The primary role of this vitamin is to keep the serum calcium and phosphate levels in the normal range. Dietary supplements are required for the best musculoskeletal health during the winter and in places with little sun exposure.

Cholecalciferol is approved for use as a dietary supplement. Vitamin D3 plays a role in hypothyroidism, osteoporosis and Vitamin D deficiency or insufficiency in both healthy and chronic kidney disease patients (CKD).

In addition to its role in bone mineral metabolism, numerous studies have linked cholecalciferol supplementation to better outcomes for several diseases, including cancer, hypertension, type 1 and type 2 Diabetes, Polycystic Ovarian Smyitavndrome (PCOS), cardiovascular disease, Multiple Sclerosis (MS), Rheumatoid Arthritis (RA), Systemic Lupus Erythematosus (SLE) and various dermatological conditions.

Benefits of vitamin B3 


Clinical depression and low vitamin D levels may coexist. Though the reason is unclear, it is possible that depression is a result of low vitamin D levels.

Sometimes, depressive behaviours, like poor eating patterns and spending less time outdoors, resulting in low vitamin D levels.

According to research, raising vitamin D levels may help with depression symptoms. It might play a part in the course of treating depression. Further studies are required to prove the claim.


Research states that calcitriol controls the renin-angiotensin system (RAS) by reducing renin expression through a VDR-mediated mechanism. In accordance with findings from several investigations, calcitriol also enhances endothelial function and reduces the severity of hypertension in general.


Calcium and vitamin D help to support the bones. The body is unable to absorb calcium from food effectively when it doesn’t receive enough vitamin D. Therefore, it takes it from the bones. This results in fractures, weakened bones and osteoporosis.  

Increasing vitamin D3 intake from diet is beneficial for raising bone density. When bone density increases, an individual is less prone to acquire diseases that weaken bones, such as osteoporosis.

Heart health 

According to research, not getting enough vitamin D may raise the risk of cardiac diseases, stroke, anxiety and chest pain. Heart failure risk is shown to decrease by Vitamin D3 intake. It also enhances heart function in those with weakened heart muscles. 

Anti-inflammatory effects 

Inflammatory diseases may respond differently to vitamin D. The chances of having asthma, allergies, acne and eczema may rise if one has low vitamin D.

According to research, pregnant women who take vitamin D supplements may reduce the risk of asthma in their unborn children. It is also advisable to consult a doctor while using vitamin supplements during pregnancy.


An individual develops stronger muscles with vitamin D intake. Studies point to a connection between high vitamin D levels and muscle strength. 

People with higher vitamin D levels were shown to have increased muscle mass, thin body type and enhanced muscle function.


Vitamin D3 is not naturally present in many foods. The flesh of fatty fish and fish liver oils are the finest sources. Cheese, cow liver and egg yolks contain smaller amounts. 

Certain mushrooms contain vitamin D2, and other types of mushrooms that are marketed commercially have higher levels of vitamin D2 as they have been purposefully exposed to a lot of ultraviolet radiation. Vitamin D is added to several foods and supplements, including cereals and dairy products.

  • Salmon
  • Swordfish
  • Sardines
  • Fish liver oil
  • Tuna
  • Vitamin D-fortified dairy and plant-based kinds of milk
  • Vitamin D-fortified orange juice
  • Animal liver
  • Egg yolk
  • Fortified grains

When 7-dehydrocholesterol, a steroid that is broken down by the sun’s UVB light or so-called tanning rays, undergoes a chemical interaction in human skin, vitamin D3 can be produced.

Dosage and Supplements 


  • Vitamin D Deficiency

The ideal Vitamin D requirement remains unclear. Few sources define it as over 30 ng/mL or falling within the range of 25 to 80 ng/mL, whilst the Institute of Medicine (IOM) defines it as being over 20 ng/mL. 

Vitamin D deficiency is defined as values below 20 ng/mL by the American Geriatric Society and Endocrine Society, whereas vitamin D deficiency is defined as levels between 20 and 29.9 ng/mL.

  • Healthy adults with Vitamin D Insufficiency

Oral supplements of 1000–2000 units taken once daily are recommended for these individuals. In three months, serum vitamin D levels might be reevaluated.

  • Vitamin D deficiency in healthy adults.

2000 unit dosage once daily with a three-month review of vitamin D blood levels.

  • For preventing osteoporosis

Adults older than or equal to 50 years old should take 800 to 1000 units of the drug orally every day.


Infants who consume less than 1000 mL of vitamin D-fortified formula each day should take 400 units of vitamin D orally.

  • Treatment for Rickets
  • For three months, give infants 2000 units orally.
  • Children require 3000–6000 oral units per day for three months.
  • Adolescents are advised to take 6000 oral units per day
  • The maintenance dose of 400–600 oral units is also recommended daily.

Although it can be taken with or without food, vitamin D is best absorbed when taken after a meal.


According to an NCBI article titled ‘Vitamin D deficiency’, a majority of vitamin D deficient patients are asymptomatic. 

Even a slight chronic vitamin D deficiency can result in hyperparathyroidism and chronic hypocalcaemia, increasing the risk of osteoporosis, fractures and falls, particularly in the elderly. 

Patients with severe and persistent vitamin D deficiency may have signs of secondary hyperparathyroidism, such as bone pain, arthralgias, myalgias, exhaustion, and weakness. 

Chronic vitamin D deficiency that results in osteoporosis can cause fragility fractures. Vitamin D insufficiency in children may manifest as irritability, tiredness, developmental delay, abnormalities in the bone or fractures.

Vitamin D toxicity 

Research suggests that on consuming larger doses of over-the-counter or prescription vitamin D supplements, vitamin D intoxication occurs. The clinical symptoms of Vitamin D toxicity manifest as hypercalcaemia. 

These include neurological signs such as confusion, apathy, agitation, irritability and in extreme circumstances, stupor and coma.

Constipation, stomach pain, nausea, vomiting, peptic ulcers and pancreatitis are some noticeable gastrointestinal symptoms. Nephrolithiasis, polydipsia and polyuria are signs of renal complaints. Heart arrhythmias can also be caused by severe hypercalcaemia.


Low blood calcium (hypocalcaemia), low blood phosphate (hypophosphataemia), rickets (softening of the bones throughout childhood) and osteomalacia are the most severe effects of vitamin D deficiency (softening of the bones in adults). Since more foods and beverages have been fortified with vitamin D over time, these issues have become less frequent.


Hypercalcaemia is the main cause of vitamin D poisoning. It is possible for anorexia, nausea and vomiting to develop, which is frequently followed by polyuria, polydipsia, weakness, anxiety and pruritus before renal failure. Proteinuria, urinary casts, azotemia and metastatic calcifications, particularly in the kidneys, are more likely to occur.


Vitamin D deficiency or insufficiency is often overlooked in most inpatient and outpatient settings. 

Routinely testing for vitamin D levels is crucial. Nonetheless, it is crucial to remember that in asymptomatic high-risk patients, testing for vitamin D insufficiency is crucial in preventing future health problems. 

Nursing mothers, elderly patients, women with osteoporosis, people belonging to certain races, hospitalised patients, those with chronic renal disease and liver disorders and people with malabsorption syndromes are among the high-risk populations.

Consulting a doctor and getting prescribed for vitamin D3 supplementation or consuming Vitamin D-rich foods along with calcium prevents deficiency diseases.


What is the difference between vitamin D3 and vitamin D?

Vitamin D3 is a type of Vitamin D and is also termed cholecalciferol. The body transforms D3 from animal foods like fish, liver and eggs into a form that may be used by the body.

What is the best food source of vitamin D3? 

Vitamin D3 is not naturally present in many foods. Fatty fish and fish liver oils are the finest sources. Cheese, cow liver and egg yolks all contain smaller amounts.

When should I take vitamin D3?

Being a fat-soluble vitamin, consuming vitamin D3 with fat helps in improved absorption. Vitamin D3 can be taken at any time of the day, along with a meal high in fat.

Who should not take vitamin D3?

Vitamin D3 supplements shouldn’t be taken by people with hyperparathyroidism, kidney illness, or excessive blood calcium levels. Prednisone, Orlistat and diuretics are a few of the drugs that might affect vitamin D. In some circumstances, there are exceptions, so talking to a healthcare professional can help.


The Information including but not limited to text, graphics, images and other material contained on this blog are intended for education and awareness only. No material on this blog is intended to be a substitute for professional medical help including diagnosis or treatment. It is always advisable to consult medical professional before relying on the content. Neither the Author nor Star Health and Allied Insurance Co. Ltd accepts any responsibility for any potential risk to any visitor/reader.

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