What is Vitamin D?
Vitamin D is a fat-soluble vitamin. That means it can dissolve in fats and oils. It’s needed for bone growth and development. It also helps cell growth and nerve, muscle, and immune function. Vitamin D is called the “sunshine vitamin” because it is produced by the body in response to sun exposure.
Why do we need Vitamin D?
• Vitamin D is responsible for controlling the balance of calcium in our body.
• Maintains the normal calcium levels and bone density.
• Aids in the reabsorption of phosphorus from the kidneys.
• Enhances the absorption of calcium and phosphorus from the intestines.
• Plays a crucial role in promoting normal bone growth.
• Facilitates the healing of fractured bones. Its significance is particularly pronounced in infants, children, and adolescents.
• Helps treat Rickets, some types of abnormal muscle contractions, Osteomalacia and Vitamin D deficiency.
What are the Different Forms of Vitamin D?
Vitamin D Comes in 2 forms:
• Ergosterol (provitamin D-2) - This type is found in plants and fungi. Ergosterol (provitamin D(2)) is converted to vitamin D(2) in grass by exposure to UV light.
• Ergocalciferol (vitamin D-2) - This type is found in food and used as a dietary supplement.
• Calciferol (vitamin D-3) - This type is formed in the body from exposure to sunlight.
What are the Sources of Vitamin D?
Though some foods have it, only few naturally contain Vitamin D. For some people, the best way to get Vitamin D is through supplements.
Cited in an article from Harvard School of Public Health, “Vitamin D supplements are available in two forms: vitamin D2 (“ergocalciferol” or pre-vitamin D) and vitamin D3 (“cholecalciferol”). Both are also naturally occurring forms that are produced in the presence of the sun’s ultraviolet-B (UVB) rays, hence its nickname, “the sunshine vitamin,” but D2 is produced in plants and fungi and D3 in animals, including humans.
Vitamin D production in the skin is the primary natural source of vitamin D, but many people have insufficient levels because they live in places where sunlight is limited in winter, or because they have limited sun exposure due to being inside much of the time. Also, people with darker skin tend to have lower blood levels of vitamin D because the pigment (melanin) acts like a shade, reducing production of vitamin D (and also reducing damaging effects of sunlight on skin, including skin cancer).”
Food Sources
Cod Liver Oil, flesh of fatty fish like salmon, swordfish, tuna fish, sardines, fish liver oils, egg yolks, cheese, beef liver, mushrooms, orange juice fortified with vitamin D, dairy and plant milks fortified with vitamin D, fortified cereals.
Shop more Vitamin D supplements online for kids and adults.
Vitamin D Recommended Intake
According to Health Direct Australia, The Australian government publishes recommended dietary intakes (RDIs) for all vitamins are as follows:
• Babies, children, teenagers and adults aged 19–50 years should have 5μg (micrograms) of vitamin D per day.
• Adults aged 51-70 years should have 10μg of vitamin D per day.
• Adults aged over 70 years should have 15μg of vitamin D per day.
In summertime, you only need to spend a few minutes during mid-morning or mid-afternoon (when UV index is 3 or more). Make sure to wear a hat and put on sunscreen since UV radiation causes skin cancer.
During autumn and winter, the UV index is lower than 3. Try to go out and do outdoor activities in the middle of the day to get your dose on Vitamin D.
See the sunshine map to see how much sun exposure you need where you are in Australia.
Signs of Vitamin D Deficiency
It is said that more than 1 in every 3 Australian adults has mild, moderate or severe vitamin D deficiency.
Symptoms of Vitamin D deficiency may not be obvious as it can only be detected by a blood test. However, Australian health authorities recommend that people with low Vitamin D take supplements — even if they do not have any obvious signs of deficiency. Especially to those who belong to the following groups:
• Older people or people living in care (such as hospitals, rehabilitation or aged-care facilities).
• People who stay indoors or cannot walk.
• People with gastrointestinal (digestive) disease.
• People taking certain medications (for example, epilepsy medicines).
• People who cover their skin for religious or cultural reasons.
• Dark-skinned people.
• Pregnant people.
• Postmenopausal people.
Impacts of Vitamin D Deficiency
Vitamin D deficiency means calcium deficiency which may result to the following:
• Osteoporosis, bone and joint pain.
• Risk of falling and bone fracture for older people.
• Risk of seizures for babies with low calcium.
• Some children may have rickets due to low calcium.
• Weakened immune system.
Can someone take too much Vitamin D?
Whilst there is no negative effect of getting too much Vitamin D from the sun, long exposures to harmful UV radiation may increase your risk of getting skin cancer. Always wear sunscreen and a hat to protect yourself.
High doses of Vitamin D when taken continually can cause Vitamin D toxicity. You will develop a condition called hypercalcaemia (where there is too much calcium in your blood) which can cause nausea, dehydration, constipation and frequent urination. More so, might progress into kidney problems like formation of calcium stones or bone pain.
If you are concerned that you have taken too much of a vitamin D supplement, call the Poisons Information Centre (13 11 26) immediately.
Bottom Line
While it’s essential to take care of your health, speak with your doctor or an accredited dietician before taking any vitamin supplement. Vitamins can supplement your diet but should not be used as a replacement for a healthy lifestyle.
Sources:
Health Direct Australia.(n.d.). Forms of Vitamin D, Vitamin D Deficiency. Retrieved from https://www.healthdirect.gov.au/vitamin-d-and-your-health
University of Rochester Medical Center. (n.d.). What is Vitamin D? Retrieved from https://www.urmc.rochester.edu/encyclopedia/content.aspx?contenttypeid=19&contentid=vitamind
Hardvard School of Public Health. (n.d.). What is Phosphorus?. Retrieved from https://www.hsph.harvard.edu/nutritionsource/phosphorus/
NIH National Library of Medicine. (n.d.). Ergosterol (provitamin D-2). Retrieved from https://pubmed.ncbi.nlm.nih.gov/21919518/
Wikepedia. (n.d.). Ergocalciferol (vitamin D-2). Retrieved from https://en.wikipedia.org/wiki/Ergocalciferol
ScienceDirect. (n.d.). 7-dehydrocholesterol. Retrieved from https://www.sciencedirect.com/topics/medicine-and-dentistry/7-dehydrocholesterol
Mayo Clinic. (n.d.). Rickets, Hypercalcemia. Retrieved from https://www.mayoclinic.org/diseases-conditions/rickets/symptoms-causes/syc-20351943
Healthy Bones Australia. (n.d.). Sunshine Map. Retrieved from https://healthybonesaustralia.org.au/your-bone-health/vitamin-d-bone-health/
