Nutrient Profile - Vitamin D - All Your Questions Answered

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There has been so much talk in recent years about Vitamin D, and yet many people are still not sure why. Vitamin D is a testament as to why we need to see constant research in the field of nutrition as almost every week we’re discovering more and more just how vital this wonderful Vitamin is. Being however, that it is a relatively new player on the vitamin field, there is a lot of confusion about what it is, how it works, how much we actually need, and how to fix it if we’re deficient. I’ve written this article with a focus on the type of questions I get asked on a daily basis, so hopefully you find it useful.

Do I need vitamin D?

The answer is YES!. We all need vitamin D, it is invaluable to our functioning and overall health, and yet can be quite difficult to get solely through our food. Research shows that one third of Australians are deficient in Vitamin D and yet many of us have only recently heard about the benefits of this multifunctional vitamin. Although being discovered in the early 1900’s, interest in vitamin D has only hit its peak in recent years, for example in 1975 there were approximately 100 articles on vitamin D published in academic journals, compared to over 1400 articles that were published in 2007. The huge increase has lead to a better understanding of this much needed nutrient, information that has now trickled through into medical and complimentary health systems around the world.

"We are in the middle of the golden age of vitamin D research. New discoveries on the health benefits of solar ultraviolet-B (UVB) light and vitamin D are being announced at a rapid pace." William B Grant, PhD

 What does vitamin D do in the body?

-        Vitamin D3 or cholecalciferol acts as both a vitamin and a hormone. A hormone is a substance in the   body that is able to affect the activity of a cell

-          Vitamin D assists in calcium absorption through the intestines

-          Research shows that a low serum levels (or blood levels) of vitamin D lead to osteomalacia, a disease that causes softening of the bones and low bone mineral density.

-          There is evidence that low serum vitamin D is associated with some cancers, and worse outcomes for other types of cancer

-          Low serum vitamin D is associated with increased mortality in the elderly.

-          Vitamin D plays a role in immune function.

-          Improving our vitamin D status has a direct effect on lowering the rate of bone fractures and improving tooth attachment

-          There is research that suggests  it plays a role in improving insulin secretion

-          Studies show vitamin D and calcium can assist in maintaining bone mineral density for those who are taking corticosteroids.

"Vitamin D deficiency is a global pandemic that has serious health consequences for children and adults. Improvement in the world’s vitamin D status could significantly reduce risk of many chronic illnesses including cardiovascular disease, autoimmune diseases, type 2 diabetes and many deadly cancers as well as infectious diseases including upper respiratory tract infections, influenza and tuberculosis." Michael F Holick, PhD, MD

How do I know if I’m low in Vitamin D?

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These days your GP can easily check for your serum vitamin D levels using a blood test. While there is conflicting information on ideal serum concentration of Vitamin D, the following is a good guideline

Cholecalciferol serum concentration of

>75nmol/L = good

50-75nmol/L = could be better

25-50nmol/L = whoops, need some help

15-25nmol/L = oh no! Hurry while there’s still time!

<15nmol/L = get me some vitamin D, STAT!

Don’t I get vitamin D from the sun?

 Most of us have heard that we get our vitamin D from the sun, and it’s true, vitamin D can be synthesized from cholesterol when our skin is exposed to the sun. However in a country that has one of the highest rates of skin cancer and who grew up with the motto ‘slip slop slap’ we may not be getting the sun exposure we need to keep our vitamin D levels adequate. Both the Cancer Council and Osteoporosis Australia suggest a small amount of time exposing your arms and face to the sun on a daily basis. The following table is taken from the Osteoporosis Australia website

Skin Type	Season	Exposed area	Time of day	Time exposed
Moderate/fair	Summer	Arms or equivalent	Mid am/mid pm	5-10 minutes
Darker skin	Summer	Arms or equivalent	Mid am/mid pm	15-60 minutes

Skin type	Season	Exposed area	Time of day	Time exposed
Moderate/fair	Winter	Arms or equivalent	Midday	7-30 mins
Darker skin	Winter	Arms or equivalent	Midday	20 mins – 3 hours

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These tables should be used as a general guideline. The Cancer Council also indicates that if you live in the northern states of Australia, you should spend time at the lower end of the scale; compared to if you live in the southern states, where you may need to spend the greater amount of time in the sun. As sunscreen absorbs the UV rays preventing them from being absorbed by the skin it is important that you are not wearing sunscreen during these specific exposure times

It is natural for our levels of vitamin D to be lower near the end of the winter months and higher at the end of the summer months due to the changes in sun exposure. Bear in mind that vitamin D is far soluble, so it stores in the fatty tissue in the body. A high level of vitamin D at the end of summer can help you get through a dark and dreary winter.  Winter therefore, is a good time to have your vitamin D checked and ensure its not dropping too low.

Can I get vitamin D from food?

Yes! Vitamin D is available from foods, and in fact the serum vitamin D test done by your doctor is based on both the vitamin D you’ve made from sun exposure, and that which you’ve gotten through food. The only problem with Vitamin D in food is that it is hard to get your full daily requirement from food alone. Some food sources of vitamin D include

Cod liver oil

Salmon cooked 100g   360IU

Mackerel cooked 100g 345IU

Sardines canned in oil 50g 250IU

Tuna canned in oil 100g 235IU

Whole egg 60g                  20IU

Fortified foods including dairy also have vitamin D

Am I at risk of having low vitamin D?

One third of Australians are deficient in vitamin D, if you fall into one of the following categories its possible you’re part of that statistic

-          If you’re elderly or in a nursing home or hospital

-          If you have darker skin the pigments of the skin are thought to inhibit the production of vitamin D when exposed to UV rays

-          If you have malabsorption issues such as crohns or celiac

-          If you cover up for cultural or religious reasons you may not be exposing enough skin to synthesize adequate vitamin D

-          If you work in an office and spend all day inside

-          If you consistently use sun protection such as sunscreen, hats and long clothing. Research shows that a sunscreen with an SPF 8 can decrease vitamin D synthesis by 95% and an SPF 15 can decrease synthesis by up to 98%

-          Babies of deficient mothers are at risk if they are breast fed as they cannot get adequate vitamin d through the breast milk

I’ve just found out my vitamin d is low, what do I do now?

Thankfully it is not particularly difficult, or expensive to get your vitamin D levels back to an acceptable level. As mentioned, a short burst in the sun at the right time of day and for the length of time suitable to you is a good start (refer to the Osteoporosis Australia tables above). You could also try including the foods that are higher in vitamin D more regularly in your diet. However, if your levels are below 50nmol/L (ask your doctor for the exact level if you’re unsure how to read your test results) you may need to consider supplementation.

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Vitamin D supplements

There are many different brands of vitamin D supplements on the market. The most important thing to look for is a reputable brand, and also, that it uses vitamin D3. Vitamin D3 is the form that our bodies use and in research has been shown to be the most effective. Cheaper brands will sometimes use Vitamin D2 which we know is around 1/3^rd the potency of vitamin D3.

You may find vitamin D3 sold as both capsules and drops, both of which are highly effective in increasing serum vitamin D quickly. Generally speaking, in Australia, vitamin D3 is sold in strengths of 1000IU.

How much vitamin D3 should I take from supplements daily?

The amount of vitamin D3 you take daily should really depend on your current vitamin D status. As a general rule the following dosages are recommended

>75nmol/L  - no vitamin D needed unless prescribed by a consulting practitioner. Try including vitamin D rich foods and getting the recommended amount of sun exposure to maintain your vitamin D status

50-75nmol/L -  try 1000-2000IU (1-2 drops or capsules) for 6 weeks to boost it a little. Also look at your food sources and your recommended sun exposure.

25-50nmol/L – 4000IU (4 drops or capsules) for 12 weeks followed by a maintenance dose of 1000IU daily. Have a follow up blood test after 3 months to check current levels. It’s important to look at lifestyle factors such as diet and sun exposure to prevent future deficiency.

Below 25nmol/L – 5000IU (5 drops or capsules) for 12 weeks followed by 2000IU daily for maintenance. Have another blood test after 3 months. Again, look at lifestyle factors hear, they will be the key to maintenance. If sun exposure is out of the question, constant supplementation may be necessary.

Can vitamin D be toxic?

Research indicates that in adults, vitamin D toxicity can occur at doses of over 10000IU daily for many months. This is an unlikely scenario in Australia where are dosage ranges are more tightly regulated. In children however the toxicity rate can be lower and therefore it is advisable to seek the guidance of a practitioner when attempting to dose children.

Vitamin D is a much needed nutrient. We are only just beginning to fully understand the implications of this vitamin/hormone on our bodies and its therapeutic benefit on our health.  With so many important functions to perform, it makes sense to keep vitamin D at the forefront of our minds and incorporate lifestyle and supplemental choices to ensure we always have enough.

Did I miss anything?

Did that help? If I’ve missed anything or you want to know more, feel free to post your questions in a comment below, or find me on Facebook – First Be Healthy.

Disclaimer

This article is not meant to treat anyone or any condition, it’s written as a general guideline, so please, see your practitioner or doctor if you have any underlying conditions. If you’re in good health I really don’t want you to rush out and dose yourself up on Vitamin D just for the sake of it. Go to your Doctor, do the test and then go from there. I say this because I don’t want you to waste either your time or money, and it’s much easier to deal with a situation when you actually know the exact situation. No ‘guessing’ with your health please!

Chris