Vitamin D

Vitamin D or the sunshine vitamin is a fat-soluble vitamin and a steroid precursor produced by the body cells in response to exposure to sunlight. Alternatively, you can take vitamin D supplements, if you are not exposed enough to sunlight or live in an area with lesser sunshine. This is because vitamin D derived from food sources like milk or eggs is never enough for your bone and overall health. Now, how do you know if you are getting enough sunlight and that it is being converted to vitamin D by your body? Read on to find the answer to this, and many other, important questions.

  1. How do I get Vitamin D from sunlight?
  2. Sources of Vitamin D
  3. Vitamin D benefits
  4. Vitamin D side effects
Doctors for Vitamin D Sources, Benefits and Side Effects and dosage

Considering that India lies closer to the equator, enough sunlight is available in most areas at most times of the year, but for getting the right amount of sunlight for your skin to produce vitamin D, you must be wary of some facts.

The most natural way of getting vitamin D is by exposing your bare skin to the sun. Skin covered under layers of clothing is not exposed enough to synthesize vitamin D. The amount of vitamin D absorbed by your body also depends on the time of exposure, its duration, angulation, the color of your skin, and of course the area of skin exposed to the sun. Rule of the thumb is to expose a larger area to the sun, like your back, instead of your face and hands, since it can absorb and convert more sunlight. Don’t worry, it does not require you to lie down in the sun for hours and get a tan. Just 15 minutes (or more, depending on skin colour) would do if it is at the right time of the day. Talking of the right time, it's important to note that it varies according to seasons and areas.

A number of researches on vitamin D suggest that it is best to expose your skin to the sun from 11 am to 1 pm during all months if you live in India. But during summer days, when the UV rays are at their peak, it is essential to protect your skin from damage and the risk of developing skin cancer. So, a timing of 9 am to 12 noon is generally prescribed and is considered safe. Also, the closer you live to the equator, the easier it is for you to get this vitamin all year long since the sun is at the best angle along the equator.

Researchers have found that the highest levels of UV rays were found in the Northern region and the least in the Northeast region within India. This means that a longer exposure time is required in the Northeast regions for more bioavailability of vitamin D. Exposure time also depends on the colour of your skin. Fairer skin types tend to absorb more sunlight than darker ones. For very fair skin types, 15 minutes in the sun would do, while around 45 minutes to an hour are essential for darker skin types to make around 10,000 to 25,000 IU of vitamin D, as suggested by researchers. Be cautious while exposing your skin out in the sun to avoid burns and other risks.

Read more: Sunburn symptoms

vitamin d3 capsules
₹729  ₹899  18% OFF

The most natural source of vitamin D is sunlight, particularly UV-B rays. When exposed enough, your skin cells (epidermis) convert sunlight into vitamin D₃ by the process of photolysis. Previtamin D₃ then gets converted into vitamin D₃ which is transported to the body cells and liver for storage.

Other sources of vitamin D are:

  • Egg yolk
  • Fishes like tuna, herring and salmon
  • Cheese
  • Beef Liver
  • Cod liver oil
  • Oysters
  • Shrimp
  • Milk, soy milk and their products.
  • Certain packaged foods like cereals and oatmeal.
  • Vitamin D supplements and tablets.

Let us discuss why vitamin D is essential for you, and how it affects your body functions.

  • Strengthens bones: Vitamin D is essential for the absorption of calcium in phosphorus in the body, the two minerals that make up the basic structure of bones. Deficiency of vitamin D can lead to weak bones which are prone to fractures.
  • Benefits for children: Vitamin D is important for proper bone growth in infants and children. A deficiency of this vitamin causes rickets in children. Supplementing 2000 IU vitamin D daily has been found to help in management of steroid-resistant asthma in children.
  • Benefits for women: Vitamin D supplementation is suggested to improve menopausal symptoms and reduce the risk of osteoporosis in women, especially after menopause.
  • Strengthens teeth: Research evidence indicates that vitamin D supplementation reduces the risk of dental caries in both children and adults. It also helps in remineralisation of teeth and preventing tooth decay.
  • Improves muscle strength: By regulating calcium levels in the body, vitamin D aids in improving muscle strength and muscle mass. It also has a positive impact on physical strength.
  • Promotes weight loss: Foods rich in vitamin D are suggested to be helpful in weight reduction by curbing appetite. It also improves exercise performance and reduces fatigue, thereby promoting weight loss.

Vitamin D for bones

The most well-known effects and benefits of vitamin D are on your bone health. Vitamin D aids the absorption of calcium and phosphate in your body from food sources and supplements. Now, as we all know, calcium is very essential for the formation of a healthy bone structure. Vitamin D thus regulates and promotes healthy bone growth in your body, making your bones stronger and giving them the right frame.

This mechanism can be disturbed in case of deficiency of vitamin D, which can lead to soft or malformed bones and an increased risk of rickets (in children) or osteomalacia (in adults). To avoid this and enhance bone mineralization particularly if you experience bone pain, supplementation with vitamin D is often suggested.

Vitamin D for children

Due to its astounding effects on bone health, vitamin D is essential during the stages of bone growth and formation, that is, among infants and children. Children are often prescribed vitamin D supplements to promote stronger bones and to reduce the likelihood of developing rickets, which develops during the growing stage of an individual.

Vitamin D has other unexpected benefits for the health of your infant/child. Supplementation with vitamin D has been evidenced to reduce the incidence of childhood diseases like eczema, atopic dermatitis and asthma, by enhancing the infant’s immunity. Supplementation with 2000 IU daily has been known to be helpful in the management of steroid-resistant asthma.

Vitamin D for elderly

It is believed that peak bone mass is attained by the third decade of life through nutrition, genetics, lifestyle and physical factors. Following this, occurs bone loss or reduction in bone mass density beginning in the fourth decade. Researchers have proven that insufficient consumption of vitamin D during these phases can accelerate the process of bone mineralisation and loss. Thus, vitamin D supplementation is often prescribed during advancing age to prevent massive bone loss.

Vitamin D reduces fractures

As discussed above, a reduction in bone mass density occurs with an advancing age, which makes the bones weaker and more prone to fractures. Researchers have claimed that a deficiency of vitamin D leads to a reduction in calcium absorption, which causes the release of calcium ions from the bone to maintain normal concentrations of calcium in the blood. Studies have also demonstrated a direct relationship between a decrease in bone mass density and an increased risk of fractures, which can be prevented by taking vitamin D in sufficient quantities either from dietary sources or as supplements. if so prescribed by your physician.

Vitamin D for women

Bone loss increases with advancing age and the effects of the same are more pronounced in women, because of the effects of menopause. Menopause refers to the discontinuation of the monthly menstrual cycle of females at the age of 45 to 55 years. This phase is often presented by mood swings, anxiety and hormonal disturbances, and an increased risk of osteoporosis.

Osteoporosis refers to the weakening of bones with age, which makes them softer and more prone to fractures. Increased loss of bone mass and strength occurs in this disease, causing characteristic ‘spongy bones’. Reduction in the levels of estrogen hormone following menopause, which has protective actions on the bone tissue, has been considered to be the reason for the excessive bone loss in menopause.

Researchers have also stated that calcium absorption sharply declines following menopause, which is responsible for the fragility of bones. Calcium absorption and regulation is said to be under the control of the hormone estrogen.

While the effects of menopause are inevitable, various researchers have suggested that vitamin D levels are closely linked with hormonal levels following menopause. It is also linked with the symptoms of mood disorders and musculoskeletal disorders experienced by women in this state.

Researchers highly recommend that higher levels of vitamin D would cause a decrease in the number of menopausal symptoms, while also improving bone density after menopause. Hence both men and women between the age of 45- 60 years should get their vitamin D levels checked routinely.

Read more: Early menopause and premature menopause

Vitamin D for teeth

Dental caries or tooth decay refers to demineralization and destruction of the tooth structure, which can or cannot be painful depending upon the structures affected. Once initiated, the disease is irreversible but treatable with the help of dental drills and filling materials. Since it is not possible to reverse tooth decay, it is essential to prevent it from happening.

While maintaining your oral hygiene and consuming less sugar is the key to prevention, research evidence also suggests that vitamin D helps to reduce the risk of dental caries when given to children and adults. Since the tooth structure is majorly made of calcium ions (calcium phosphate), dietary supplementation with vitamin D at this stage will help to channelize calcium ions, resulting in stronger teeth that are more resistant to decay.

Read more: Five foods to make your teeth and gums stronger 

Vitamin D for muscles

Vitamin D has a positive impact on muscle strength and mass and also on the physical strength, capabilities and performance of an individual. It regulates the calcium levels of the body, which help in regulating muscle strength and functioning and deficiency of this vitamin causes muscle cramps. Several studies have also reported a significant reduction in the rate of falls among individuals, which is suggestive of improved muscle mass and balance. The impact of vitamin D on muscle fibres and its morphology is yet to be studied.

Vitamin D weight loss

Foods rich in vitamin D often have appetite suppressant actions, which helps in weight loss. Individuals who are already on a restrictive diet for weight reduction are often recommended to add vitamin D rich foods in their diet, to boost their energy levels, which prevents fatigue and dizziness and enhances their exercise performance. This ensures that the journey of weight loss is healthy and less stressful.

Read more: Seven common weight loss mistakes

Are you also troubled by obesity and are not able to lose weight even after a lot of efforts, then start using myUpchar Ayurveda Medarodh Weight Control Tablet today and control your weight.


Vitamin D and cancer

It has been a common observation that people living in areas of sunshine are less likely to develop certain cancers. Researchers have often debated the relationship of this observation with higher levels of vitamin D in them. In fact, lower levels of vitamin D have been suggestive of certain types of cancers. Majority of studies have proven the protective relationship of vitamin D on the body for reducing the risk of cancer, particularly colorectal cancer. Thus, vitamin D supplements have often been suggested to reduce cancer risk and mortality.

Vitamin D dosage - Vitamin D deficiency

Dosage of vitamin D depends on your body needs and requirements, and varies according to gender, age, medical conditions and area/geographic location. Despite the good availability of sunlight in our country, Indians often suffer from lower levels of vitamin D because of poor absorption from the skin owing to higher skin pigmentation and the topical application of sunscreen to prevent sun damage.

As per Indian Council of Medical Research, a recommended daily intake of 400 IU is indicated for Indians not receiving vitamin D from sunlight. The normal levels of vitamin D in the blood are 20 nanograms/millilitre to 50 ng/mL for healthy individuals. A value lesser than 12 ng/mL is indicative of vitamin D deficiency.

Vitamin D can be administered daily, weekly, monthly or quarterly to maintain normal levels of the vitamin in the blood, as reflected by the 25-hydroxy vitamin D blood test.

In order to treat severe deficiencies, a high bolus of 300,000 IU is given, followed by frequent lower concentrations. In children, vitamin D deficiency is treated by administering 50,000 IU of vitamin D3 weekly for 6 to 8 weeks, after which follow up doses of 600 to 1000 IU per day are given monthly, which require to be continued for a year. (1 IU=0.025 mcg)

Find best medical apps

Some of the common side effects of prolonged vitamin D supplementation are:

In very high amounts, vitamin D can cause hypercalcemia (characterized by muscular pain, disorientation and confusion, muscle weakness and extreme exhaustion and thirst), kidney damage or kidney stones.

Dr. Dhanamjaya D

Dr. Dhanamjaya D

15 Years of Experience

Dt. Surbhi Upadhyay

Dt. Surbhi Upadhyay

3 Years of Experience

Dt. Manjari Purwar

Dt. Manjari Purwar

11 Years of Experience

Dt. Akanksha Mishra

Dt. Akanksha Mishra

8 Years of Experience


  1. Y. Lhamo, Preeta Kaur Chugh, C. D. Tripathi. Vitamin D Supplements in the Indian Market. Indian J Pharm Sci. 2016 Jan-Feb; 78(1): 41–47. PMID: 27168680
  2. Cedric F. Garland et al. The Role of Vitamin D in Cancer Prevention. Am J Public Health. 2006 February; 96(2): 252–261. PMID: 16380576
  3. Song M et al. Plasma 25-hydroxyvitamin D and colorectal cancer risk according to tumour immunity status. Gut. 2016 Feb;65(2):296-304. PMID: 25591978
  4. National Cancer Institute [Internet]. Bethesda (MD): U.S. Department of Health and Human Services; Vitamin D and Cancer Prevention
  5. Lisa Ceglia. Vitamin D and Its Role in Skeletal Muscle. Curr Opin Clin Nutr Metab Care. 2009 Nov; 12(6): 628–633. PMID: 19770647
  6. Lars Rejnmark. Effects of Vitamin D on Muscle Function and Performance: A Review of Evidence from Randomized Controlled Trials. Ther Adv Chronic Dis. 2011 Jan; 2(1): 25–37. PMID: 23251739
  7. Khosravi ZS, Kafeshani M, Tavasoli P, Zadeh AH, Entezari MH. Effect of Vitamin D Supplementation on Weight Loss, Glycemic Indices, and Lipid Profile in Obese and Overweight Women: A Clinical Trial Study. Int J Prev Med. 2018 Jul 20;9:63. PMID: 30123437
  8. Erin S. LeBlanc et al. Vitamin D levels and menopause-related symptoms. Menopause. 2014 Nov; 21(11): 1197–1203. PMID: 24736200
  9. Daniel D. Bikle. Vitamin D and Bone. Curr Osteoporos Rep. 2012 Jun; 10(2): 151–159. PMID: 22544628
  10. Eamon Laird, Mary Ward, Emeir McSorley, J.J. Strain, and Julie Wallace. Vitamin D and Bone Health; Potential Mechanisms. Nutrients. 2010 Jul; 2(7): 693–724. PMID: 22254049
  11. Yoshida T, Stern PH. How vitamin D works on bone. Endocrinol Metab Clin North Am. 2012 Sep;41(3):557-69. PMID: 22877429
  12. Marwaha RK. Regional and seasonal variations in ultraviolet B irradiation and vitamin D synthesis in India.. Osteoporos Int. 2016 Apr;27(4):1611-1617. PMID: 26630977
Read on app