Did you know vitamin D is really not a vitamin. Vitamins are special nutrients that the body needs but cannot make on its own, so they must be obtained from what we eat or by supplements. Our bodies actually make vitamin D in our skin when it is exposed to good sunlight, therefore Vitamin D is considered a hormone. Vitamin D is an essential nutrient that helps your body absorb the calcium it needs to keep your bones and muscles strong and healthy.
What happens if I don't have enough vitamin D?
Children and infants who lack vitamin D develop the condition called rickets, which causes bone weakness, bowed legs, and other skeletal deformities, such as stooped posture.
Adults who lack vitamin D are at risk of developing Osteoporosis (meaning 'porous bones'), which is a condition that causes bones to become thin, weak, fragile and more susceptible to fracture. Osteoporosis occurs when your bones lose calcium and other minerals. Vitamin D is required to help your body to absorb calcium to help build strong bones.
People with very low levels of vitamin D (moderate to severe deficiency) are the most at risk of developing health problems. A number of diseases have been linked to low vitamin D levels such as increased risk of death from cardiovascular disease, cognitive impairment in older adults, severe asthma in children and cancer. Research suggests that vitamin D could play a role in the prevention and treatment of a number of different conditions, including type1 and type 2 diabetes, hypertension, glucose intolerance, multiple sclerosis, severe symptoms of COVID.
People most at risk of vitamin D deficiency are the elderly and people with certain medical conditions such as liver disease and kidney disease, and those with problems absorbing food, including cystic fibrosis, coeliac disease and inflammatory bowel disease. Some medicines can also contribute to vitamin D deficiency. A blood test can confirm whether you have a vitamin D deficiency.
Where do we obtain Vitamin D?
Vitamin D is obtained from 3 sources:
Most Australians get their vitamin D when they expose bare skin to ultraviolet B (UVB) light from the sun. But we all know that increased sun exposure can lead to increased risk of developing skin cancer. So how much sun exposure is the right amount? Recommendations on this are a little tricky because a fair-skinned person might get enough vitamin D from 15 minutes of sun exposure per day, whereas someone with darker skin might require an hour or two of sun exposure to get enough Vitamin D. Other factors that impact your ability to make vitamin D from sunlight include : the time of day, how far you live from the equator, how much skin you expose to sunlight and whether you’re wearing sunscreen. People who live farther away from the equator typically need more sunlight because the sun’s UV rays are weaker in these areas.
Be sensible with sun exposure and make sure not to burn your skin. Also, never use a solarium to boost vitamin D levels because they emit dangerous levels of ultraviolet (UV) radiation that increase your risk of skin cancer.
If you live further from the equator or need to avoid sun exposure you will need to obtain a larger proportion of your vitamin D from foods, particularly through the winter months. Foods that contain small amounts of vitamin D include :
Fatty fish, like salmon, tuna, and mackerel
Beef liver, some cheeses, and egg yolks
Foods with added vitamin D, such as milk, orange juice, and cereal
Infant formula is also fortified with vitamin D in Australia.
Other dairy products — such as yogurt and cheese — are typically not fortified with vitamin D.
It can be difficult to get enough vitamin D from food so it may be easier to take a vitamin D supplement. Experts recommend 600 international units (IU) of vitamin D per day for adults up to age 70, and 800 IU for people 71 and older.
Vitamin D supplements come in many different strengths and dosages. They can be low dose — which you take every day — or high dose, which you take monthly or less frequently.
Too much vitamin D can also cause health problems including weight loss, heart rhythm problems or damage to the heart, blood vessels and kidneys.
It’s not possible to get too much vitamin D from sunlight, but if you are taking vitamin D supplements it’s important to speak to your doctor or pharmacist to check you are taking the right dose.