We always seem to hear more about it in the winter months. Well there is a lot to share, year round actually.
Vitamin D is both a nutrient we eat and a hormone our bodies make. Yes, it’s now understood to be and behave as a hormone.
Few foods naturally contain vitamin D, though some foods are fortified, such as milk and bread; getting enough vitamin D from fortified foods alone would be a challenge. For most people, the best way to get enough vitamin D is by taking a supplement.
There are two main forms of vitamin D:
- Vitamin D2 (ergocalciferol): Found in plant foods like mushrooms.
- Vitamin D3 (cholecalciferol): Found in animal foods like salmon, cod and egg yolks. (With this being more effective in raising vitamin D blood levels than D2)
Before your body can use dietary vitamin D, it must be “activated” through several steps.
First, the liver converts dietary vitamin D into the storage form of vitamin D. This is the form measured in blood tests. Later, the storage form is converted by the kidneys to the active form of vitamin D used by the body.
Both D2 and D3 are naturally occurring forms produced in the presence of the sun’s UVB rays, hence the nickname “The Sunshine Vitamin.” Sunlight remains the best natural source of vitamin D3 as the UVB rays from sunlight convert cholesterol in your skin into vitamin D3. It doesn’t take much exposure; only 15 minutes of lovely sun exposure is enough….if you live close to the equator. Sadly, UVB light is weaker at higher latitudes above the equator, such as in Canada, thus making it challenging to get the vitamin in the summer months and then we have the limited sunlight hours in the winter months.
Other factors that limit our production of vitamin D:
- Use of sunscreen; correctly applied sunscreen can reduce vitamin D absorption by more than 90%. Because UV rays can cause skin cancer, it is essential to avoid excessive sun exposure, so ditching sunscreen is not the answer.
- We are wearing full clothing that covers most of the skin.
- We are spending minimal time outdoors.
- People with darker skin tend to have lower blood levels of vitamin D because the pigment (melanin) acts like a shade, reducing the production of vitamin D. Roughly 42% of people in the US have a vitamin D deficiency, which rises to 82.1% of black people and 69.2% of Hispanic people.
The usual range of vitamin D falls between 50 to 125 nmol/L. When your serum levels are down below 50 nmol/L, you have a deficiency but if you let your serum vitamin D levels get above 125 mol/L as you may experience have adverse effects. According a study published in the European Journal of Clinical Nutrition (Vitamin D deficiency 2.0: an update on the current status worldwide), 7.4% of Canadians have severe vitamin D deficiency below 30 mol/L and 37% have serum vitamin D levels below 50 nmol/L.
Vitamin D testing is available but has yet to be covered by provincial health care in Alberta since 2015. Alberta’s provincial guidelines state: Because vitamin D supplementation in the general adult population is safe and probably necessary, it is reasonable to advise supplementation without testing. You can still get a vitamin D level done, perhaps at a private lab, you may need to get a requisition form and you will have to pay out of pocket.
There are a host of functions that vitamin D plays a role in:
- Improve calcium absorption
- Prevent osteomalacia (bone softening) and osteoporosis (weak bone) in adults, thus preventing fractures
- Prevent rickets in children
- Maintain optimal function of parathyroid glands
- Keep your bones strong
- Reduce body inflammation
- Promote your immune system
- Modulation of the following processes; cell growth, neuromuscular function, and glucose metabolism
More recently, research shows that vitamin D may play a role in depression, possibly chronic fatigue and reduce your risk of heart disease and certain cancers.
Researchers have noted that many people with depression have low vitamin D levels and there seems to be a possible associations between depression and low vitamin D. Is depression the cause of lower vitamin D levels or do low levels lead to depression? While some high quality studies have noted that various groups of people experience improvements in symptoms of depression after they start taking vitamin D supplements, others found that taking 2,000 IU per day of vitamin D for 5 years did not lead to any significant differences in depression scores compared with taking a placebo.
Various studies examined the link between vitamin D blood levels and cancer. Animal and laboratory studies have found that vitamin D can inhibit the development of tumours and slow the growth of existing tumours, including those from the breast, ovary, colon, prostate, and brain. In humans, epidemiological studies show that higher serum levels of vitamin D are associated with substantially lower rates of colon, pancreatic, prostate, and other cancers, with the evidence strongest for colorectal cancer.
A promising Archives of Internal Medicine report suggests vitamin D supplements may reduce overall mortality rates.
Vitamin D seems to influence various areas of our health; In contrast, some studies are not as conclusive as others; we can agree that Canadians should supplement with some vitamin D.
It is believed that consuming 2,000 IU daily would help 50% of people reach an adequate vitamin D blood level of 82.4 nmol/l.
Can you get too much?
Yes, but it is very rare. Hypervitaminosis D develops after uncontrolled use of vitamin D mega doses. In healthy individuals it is caused by prolonged use (months) of vitamin D dosing, probably in excess of 10,000 IU/day.
How Much Vitamin D Do You Need for Optimal Health?
If you look on the Health Canada Website, they suggest taking a daily supplement containing 400 IU of vitamin D, which has yet to been updated since 1997. It is currently under review as many experts believe the guidelines are far too low.
Many studies have shown that you need to consume more vitamin D than the guidelines recommend to reach blood levels linked to better health outcomes, optimal being between 50 nmol/L and 125 nmol/L.
Supplementing with vitamin D is quite safe for most individuals. Based on current research, consuming 2,000–5,000 IU of vitamin D daily should be ideal for most people to achieve the the target blood levels. If looking for a more therapeutic outcome then target closer to the 5000IU/day.
While taking 2-5 pills (1000 iu/tab) daily may not be favourable to most people, there is a good alternative! We carry Vitamin D drops. Each drop delivers 1,000 IU and can easily be added to a glass of water, juice or a smoothie.
Contact one of our locations for more information on Vitamin D or about purchasing Vitamin D Drops.
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