Vitamin D: The Vital Vitamin
Vitamin D is known as the sunshine vitamin because it is produced in the skin when our bodies are exposed to sunlight.
The best time of the day to expose your body to the sun, according to some studies, is between 11 am and 2 pm. It is during this time period that UVB rays are the most intense. One study suggests that it is also safer as afternoon sun exposure is more likely to cause dangerous skin cancers. Between 10 - 30 minutes per day several times a week will be the right amount of time to keep vitamin D levels in the body at a healthy level.
Individuals with darker skin need up to 6 times more sunlight than lighter-skinned people to get sufficient vitamin D.
Once absorbed by the skin, Vitamin D is still in its inactive form. It must first travel through the liver and then to the kidneys to become biologically active and available for the body to use.
This versatile vitamin is linked to numerous health benefits from supporting the immune system, to bone and brain health, modulation of blood sugar balance, and cardiovascular functioning. It is also involved in the critical process of regulating up to 2000 genes in our bodies.
In contrast, being deficient in the sunshine vitamin can cause a number of health problems like osteoporosis, depression, fatigue, weight gain, bone and back pain, as well as muscle weakness and a compromised immune system.
Signs of Vitamin D Deficiency
The signs of a vitamin D deficiency are very subtle so most of us don’t know that we are deficient. Today, many of us tend to spend more time indoors so we don’t get the correct amount of sun exposure to get our daily needs met. As we age, our ability to absorb vitamin D also decreases.
Using sunscreens also blocks the body’s ability to absorb vitamin D. (A safer way to protect the skin from sun damage and skin cancer is to use topical or oral antioxidant supplements. For example, a topical vitamin C and E combined with green tea extract, ferulic acid or other antioxidants can help prevent skin cancer and skin ageing)
People who require high doses of vitamin D from sun and supplements include:
- Individuals who are housebound,
- people living in colder climates,
- those suffering with renal disease, osteoporosis or osteopenia (soft bones), inflammatory bowel or celiac disease,
- and people who are taking anticonvulsants.
- Dark-skinned people are more likely to have a vitamin D deficiency as increased melanin lowers the skin's ability to produce vitamin D.
It is, therefore, reasonable to assume that most people are vitamin D deficient and should be taking a Vitamin D supplement.
Vitamin D and viral infections
Insufficient levels of vitamin D can lead to a compromised immune system. This can make us susceptible to viral, fungal and bacterial infections. It can also lead to the development of autoimmune diseases like rheumatoid arthritis, lupus, inflammatory bowel disease, psoriasis and multiple sclerosis.
A study conducted by Trinity College, Dublin found that adults who took Vitamin D supplements were 50 per cent less likely to contract a chest infection.
Contracting a viral respiratory infection like COVID-19 would be harder to beat if you were Vitamin D-deficient. Vitamin D may not be able to prevent you from contracting viruses, like the coronavirus, but it can help your immune system fight it off.
Vitamin D and Cardiovascular Disease
There is evidence from a 7-year study, that increased levels of vitamin D led to a lower risk of dying from all causes, especially cardiovascular disease.
Data revealed that there was a greater prevalence of peripheral arterial disease in subjects with the lowest levels of vitamin D compared to subjects with the highest levels. (Trusted Source 1)
Vitamin D and multiple sclerosis
There is evidence that in multiple sclerosis, the immune cells are not regulated properly. Studies suggest that vitamin D acts as an immune modulator.
Canadians have one of the highest rates of multiple sclerosis in the world. For 6 months of the year the sun in Canada is not intense enough to manufacture sufficient amounts of vitamin D in the skin.
Children, who were later diagnosed with multiple sclerosis, had far lower levels of vitamin D compared to their peers.
Another finding showed that adults living in northern countries get less sun exposure and may have a higher risk of multiple sclerosis. (Trusted Source 2)
There is also a growing body of evidence that links low vitamin D with disease, including breast and colon cancer, heart disease, diabetes and tuberculosis.
Vitamin D and diabetes
Recent research has demonstrated that those who receive high amounts of vitamin D during childhood have a lower risk of developing type 1 diabetes later on in life, the greater the amount of vitamin D, the greater the benefit.
Type 1 diabetes is caused by the insulin producing beta cells of the pancreas being destroyed by our own immune system. This process starts early in childhood. (Trusted Source 3)
Vitamin D also helps the body to produce hormones that regulate blood sugar. Having low levels of vitamin D makes you more susceptible to developing type 2 diabetes.
Vitamin D and breast cancer
Research suggests that Vitamin D plays a vital role in the prevention of breast cancer. It may play a role in controlling breast cell growth and may be able to stop the growth of breast cancer cells. Studies indicate that women with low levels of vitamin D may have a higher risk of developing breast cancer.
The conclusion of this combined research was that the intake of 2000 IU/d of vitamin D3, and, when possible, moderate exposure to sunlight, could raise serum 25(OH)D to 52 ng/ml, a level associated with the incidence of breast cancer being reduced by as much as 50%.
In 2006, researchers at the Imperial College of London found that Vitamin D levels were higher in women with early-stage disease than in women whose breast cancer had progressed to a more advanced stage. It concluded that for women already diagnosed with breast cancer, vitamin D may slow the progression of the disease.
In August 2007 researchers at the University of California reported that an estimated 250 000 cancers of the colon and 350 000 breast cancer cases could be prevented worldwide each year with vitamin D supplementation. They recommended doses of 2000 IU/d for a meaningful reduction in breast cancer. (Trusted Source 4)
Studies on rheumatic arthritis also show that women who get the right amount of vitamin D are less likely to suffer from chronic widespread pain. Many people suffering from chronic pain have low vitamin D levels and that supplementing with vitamin D can relieve certain types of pain.
Vitamin D and anti-ageing
Recent studies suggest that high levels of vitamin D have a strong association with increased leukocyte telomere length. This is important for one’s health and longevity.
Leukocytes (white blood cells) help the body fight off infection and disease. Like all cells, leukocytes contain our chromosomes, which consist of DNA and associated proteins. Telomeres are tiny terminal segments at each end of the DNA molecule that protect the chromosome from deterioration
During cell division, as the telomere ends become shorter, an enzyme called telomerase replenishes and lengthens the ends of these chromosomes. Without this protective action some chromosome material would be lost with each replication. The result would be the deterioration of the cell function and overall health.
The length of telomeres decreases in certain cells as we get older.
By increasing levels of vitamin D, we could extend the length of the telomere which could be very beneficial as an anti-aging tool in preserving cellular and DNA health.
Vitamin D and brain function
There is evidence that low vitamin D levels increase depression in the elderly. Our brains contain vitamin D receptors and studies have shown that vitamin D plays an essential role in achieving and maintaining a healthy mind.
In animal and laboratory studies vitamin D has been shown to protect neurons and reduce inflammation. This means that in the future we could potentially treat depression and cognitive functioning with measured doses of vitamin D. (Trusted Source 5)
How Much Vitamin D Do I Need?
Even a healthy well-balanced diet cannot provide you with enough vitamin D if you do not get the right amount of exposure to the sun.
Most of our vitamin D needs should come from direct sunlight but if this isn’t always possible, especially during the Winter months, we should be taking a vitamin D3 supplement.
Babies under a year need a daily supplement of 8.5-10 micrograms if they are not having at least 500ml of fortified formula milk.
Healthy adults and children over the age of one should be taking a daily supplement containing 10 micrograms (400 IU) of Vitamin D3.
Very few foods in nature are good sources of vitamin D. It is usually fortified foods like milk formula and cereals that provide the best food sources of vitamin D.
Natural foods that contain reasonable amounts of vitamin D include oily fish like salmon, mackerel, sardines, trout, herring and kippers. Small amounts of vitamin D can be found in egg yolks, meat and milk.
Overdosing on vitamin D is extremely rare but can occur with extremely high doses (over 60 000 IU a day) This can result in vitamin D toxicity where there is a buildup of calcium in the blood. The symptoms are nausea, vomiting and frequent urination. Long term vitamin D toxicity can result in bone loss and kidney failure.