Vitamin D is a very important factor in determining and assisting us to maintain overall health.
Function of adequate Vitamin D levels:
- Helps maintain healthy bones and teeth by aiding calcium absorption
- Boosts our immunity
- Supports healthy skin and muscle strength
- Supports heart health and helps lower blood pressure, total and “bad” LDL cholesterol
- Protects brain cells
- Decreases inflammation in the body which reduces the likelihood of developing various cancers such as skin, breast, prostate and colon
- Reduces the risk of developing some autoimmune disorders such as Lupus, Rheumatoid Arthritis, Multiple Sclerosis, and Type 1 Diabetes
Having low Vitamin D levels increases the risk of developing heart disease, type 2 Diabetes, various cancers, autoimmune diseases, some infectious illnesses, neurological disease and muscle pain and weakness.
Our bodies can make Vitamin D from sunlight and we also get small amounts from a few foods that we eat. Vitamin D supplements are also available. The Vitamin D made in our bodies from sunlight exposure plus supplements has to be changed several times in our bodies before it can be used. This process involves our liver and kidneys.
We can store up to 6 months worth of Vitamin D in our bodies which is just as well when we tend to have less sun exposure over the cooler months. We deplete these stores over Winter. Everyone metabolises Vitamin D differently, for instance, 2 people can have the same sun exposure and whilst one may have healthy Vitamin D levels the other person may have insufficient levels. We are less able to synthesize Vitamin D through our skin as we age. Sun- block and glass inhibit Vitamin D absorption.
Who is at risk of having low Vitamin D levels:
- Those who have minimal sunlight exposure either by choice or due to other circumstances such as office workers, shift workers or who cover their skin for medical, cultural or religious reasons
- The elderly and any persons who may be institutionalised or home bound
- Those who are hospitalised for prolonged periods of time
- Those with darker coloured skin pigmentation
- Those with obesity
- Those with kidney or liver disease
- Those with pancreatic insufficiency or Pancreatitis
- Anyone with mal-absorption issues such as Crohn’s Disease, Ulcerative Colitis, Coeliac Disease, Inflammatory Bowel Disease and Cystic Fibrosis
- Those who have undergone gastric bypass surgery
- Those taking certain medications such as some cholesterol lowering medications (not statins), steroid medications such as Prednisolone, some anti-seizure drugs, anti-tuberculosis drugs and some weight loss drugs that interfere with fat metabolism
- Those with high or low thyroid function
- Those with Osteoporosis
- Premature babies
- Breast fed babies
Having a blood test is the only reliable way to know whether your Vitamin D level is normal, insufficient or deficient. Talk to your GP about getting your Vitamin D level checked if you have any of the preceding risk factors.
Food sources of Vitamin D
Vitamin D is found in fatty fish such as salmon, herrings, mackerel, sardines and tuna as well as in egg yolks, beef liver and fortified foods including some margarine.
Safe sun exposure
It is necessary to balance the risk of developing skin cancer with safe sun exposure to allow sufficient time for Vitamin D to be absorbed. People with darker skin pigmentation may need greater sun exposure or supplemental Vitamin D to normalise their levels.
Generally speaking the face hands and arms should be exposed and the best times of day and amount of exposure vary from month to month and state to state.
Recommended Sun Exposure times in minutes which result in 1/3 MED for people with moderately fair skin at different times of day. (1/3 MED is thought to be equivalent to producing 1000 international units of cholecalciferol, Vitamin D.
|Region||December to January||July to August|
|At 10:00am or 2:00pm||At 10:00 or 2:00pm At 12:00pm|
|Cairns||6-7 mins||9-12 mins 7 mins|
|Townsville||5-7 mins||9-13 mins 7 mins|
|Brisbane||6-7mins||15-19 mins 11 mins|
|Perth||5-6 mins||20-28 mins 15 mins|
|Sydney||6-8 mins||26-28 mins 16 mins|
|Adelaide||5-7 mins||25-38 mins 19 mins|
|Melbourne||6-8 mins||32-52 mins 25 mins|
|Hobart||7-9 mins||40-47 mins 29 mins|
|Auckland||6-8 mins||30-47 mins 24 mins|
|Christchurch||6-9 mins||49-97 mins 40 mins|
Table sourced from Medical Journal of Australia 2005
NB: Solariums should never be used to try to boost Vitamin D levels as they have been shown to increase the risk of skin cancer.
Vitamin D Supplements
There are a wide range of Vitamin D supplements available, ranging from relatively low doses of 400 international units up to 100,000 international units. These are available in tablet, capsule, liquid drops and powder forms. Vitamin D3 is the best absorbed form of Vitamin D.
Should your levels be insufficient ask your GP or Pharmacist to guide you as to the best Vitamin D supplement to take. If your levels are very low you may need relatively high doses for a few weeks or months to restore your levels to the normal range followed by a repeat Vitamin D test 3-6 months later. A smaller maintenance dose of daily Vitamin D may then be taken if you have achieved a normal range and the cause of your Vitamin D deficiency is not corrected.
It is generally best to avoid taking your supplementation of Vitamin D from fish liver oils (not to be confused with fish oil). Fish liver oils also contain Vitamin A which can lead to Vitamin A toxicity and serious and potentially fatal side effects.
When taking a Vitamin D supplement take it with your highest fat content meal of the day as it requires fat to be metabolised. Use healthy fats such as olive oil, avocado, nuts or other healthy vegetable oils.
As with most things it is possible to take too much Vitamin D- this is more likely to happen if people regularly take more than 5000 international units each day for a prolonged period of time and can result in some unpleasant and potentially dangerous side effects. It is best to regularly liaise with your GP about the best dose to take if you are Vitamin D deficient.
The importance of having your Vitamin D level checked
Vitamin D deficiency can have few symptoms until damage has been done.
Knowing what your Vitamin D level is and taking appropriate corrective action if required can reduce your risk of developing a wide range of chronic diseases and optimise your immune system and bone health. If you have any of the risk factors for low Vitamin D see your GP and ask to have your Vitamin D level checked.