• Ann Taylor

Caution re vitamin D supplementation

Have you had your vitamin D tested recently? What time of the year was it tested? How did your result compare with the following reference range?

Test result Australian standard 50-140 nmol/L Reference range >59 nmol/L Adequate during summer >49 nmol/l Adequate at end of winter 30-49 nmol/L Mild deficiency 12.5-29 nmol/L Moderate deficiency <12.5 nmol/L Severe deficiency Unless you are someone at high-risk from moderate to severe vitamin D deficiency, meaning a test result below 25 nmol/L (NPS Medicinewise, 2014), you cannot get vitamin D tested under Medicare for screening purposes. The primary concern about such low levels of vitamin D is the risk to bone health, because of vitamin D’s role in calcium absorption from food we eat. Low calcium absorption impairs bone mineralization, causing rickets in children and osteomalacia (soft bones) in adults. Sustained low blood calcium can result in demineralization of bones, leading to osteoporosis and increased risk of bone fractures – especially as we age.

However vitamin D has many other roles, affecting expression of 1000’s of genes, immune system function, insulin secretion, blood pressure, mental health. A common naturopathic medicine view is that vitamin D levels should be higher to help protect against various diseases, including autoimmune-, cardiovascular- and metabolic disease, some cancers, microbial and respiratory disease, some neurological and mental health conditions (Nowsen etal, 2012). Thus, 100-160 nmol/L is considered to be a healthy optimal range, and a naturopath is more likely to recommend vitamin D supplementation to raise your measured vitamin D.

However another disparate view is that there has not been enough research done to prove the efficacy or safety of vitamin D supplementation, with evidence linking both low and high levels of vitamin D with increased risk of mental disease and mortality (Henderson, ud) and lack of evidence that vitamin D supplementation is helpful for autoimmune conditions (Albert, Proal and Marshall, 2009). Thus 23-60 nmol/L is considered a natural homeostatic range.

Quite a difference! Who to believe? Vitamin D is not a simple story…

Vitamin D is a hormone

Not, “D” is NOT a vitamin, it’s really a hormone that our bodies make from cholesterol in our skin, with exposure to UVB solar radiation. As a hormone, it regulates activity and growth of cells. Our bodies self-regulate naturally synthesized hormone, only making what it needs.

Given that this hormone has multiple diverse roles, how do we know what type of imbalance we might create by artificially raising this hormone level with a synthetic substitute? For example, the anti-inflammatory effect of vitamin D may be helpful in autoimmune conditions, or the immunosuppressive effect may inhibit the body’s ability to heal, and potentially worsen disease progression.

If one is supplementing, one really needs to have blood levels assessed to ensure it stays within a safe range, but medical doctors and naturopathic doctors have different views about what this safe range is.

Excess vitamin D is toxic

Understand that this measured vitamin D is the stable, inactive form called 25-hydroxyvitamin D (25(OH)D) or calcidiol. The vitamin D that actually does the work is an activated form called dihydroxyvitamin D (1,25(OH)2D) or calcitriol, converted in our kidneys from calcidiol.

Sustained high levels of 1,25(OH)2D will cause calcium to be extracted from your bones, if dietary calcium is inadequate. This can lead to a condition called hypercalcemia – abnormally high blood calcium. This excess blood calcium may deposit in soft tissue, causing kidney stones, calcification of vascular vessels and the heart, and cardiac arrhythmia.

Hence raising vitamin D without knowing how this is being converted to the activated form, may cause adverse effects of de-mineralising bone when 1,25(OH)2D is elevated.

Flawed testing

If we’re interested in bone health, we really need to know what our active vitamin D level is, but this is difficult to measure accurately as it is unstable, with a short half-life. Hence the vitamin D test for the stable, inactive 25(OH)D is currently the medical industry standard.

If you do get 1,25(OH)2D tested (privately), these are the reference ranges (Waterhouse etal, 2011 and pathology report from Douglas Hanley Moir, June 2012):

23-37 pg/mL or 65-176 pmol/L

When 1,25(OH)2D is high and 25(OH)D low, it is called dysregulated vitamin D, a risk for mineral and metabolic imbalances.

Non-specific reference range

We are all been assessed against a single reference range that does not take account of factors that might affect what the ideal physiological range is for a group of people (gender, physical attributes, location etc.).

Healthy bones need more than vitamin D and calcium

Magnesium, silicon, boron, vitamin C, inositol, L-arginine and vitamin K2 are also known to be essential for our body to be able to use calcium for healthy bone structure (Price, Langford and Liporace, 2012). But it is magnesium that is absolutely key to regulating and controlling calcium metabolism. More explanation here.

If you don’t have enough magnesium, the hormones, including vitamin D, that control calcium levels and distribution in our bodies can’t do a proper job (Dean C, 2012); and this adversely affects more than bone health.

Serum magnesium is not a good measure of magnesium status, given that most magnesium is inside cells. But Vorman & Ochsenham (2016) suggests a normal range should be:

Serum magnesium 0.85 – 1.1 mmol/L

Dean (2012) recommends the magnesium red blood cell (RBC) test and advises the following test results:

Normal range Optimal range 4.2-6.9 mg/dL 6-6.5 mg/dL 1.7-2.8 mmol/L 2.5-2.7 mmol/L I’ve never had my magnesium tested, but I have signs and symptoms of magnesium deficiency, which I can resolve with magnesium supplementation.

Some personal experience

9 years ago when I had really dry “tessellated skin” on my arms and legs (calcium deposited in soft tissues). and off-the-chart calcium levels in my hair, assessed by hair mineral analysis, the doctor I consulted at the time was concerned about bone demineralization, and advocated calcium supplementation. I’d read enough to be cautious about this advice (primarily concerned about cardiovascular risks of calcification).

Instead I increased my magnesium intake through food and supplementation as well as my fat intake especially essential fatty acids in oily fish and cod liver oil. My skin improved immensely! And my next hair mineral analysis showed calcium levels in the normal range.

Everything feels better when I up my magnesium levels! It’s probably the single most important supplement that I do recommend to almost everyone.

Cod liver oil is another…it provides some vitamin A and vitamin D as well as the healthy essential fatty acids that people take fish oil capsules for. Health tips for upping your vitamin D naturally

Sun exposure In summer, get 10-15 minutes of UVB sun exposure between 10am and 2 pm, without sunscreen, 3-4 X weekly. Stretch this to 30 minute in winter time, when the sun is lower in the sky.

Exercise Get at least 3 hours a week of vigorous exercise, preferably outdoors, e.g. running, jogging, playing basketball or soccer, because the body’s physiological response to hormones stimulated by vigorous exercise also raises vitamin D levels (Chomiste etal, 2011).

Diet Include three serves weekly of oily fish, being salmon, sardines or mackerel to provide healthy essential fats. Vitamin D is fat soluble. We need healthy fats, not low-fat, high carbohydrate diets.

Eat lots of food sources of magnesium and consider supplementing with a good quality, bioavailable form (seek advice), because it is very easy to become depleted in magnesium. _____________________________________________________________________


Albert P, Proal A & Marshall T, 2009, Vitamin D: The alternative hypothesis, viewed online 17 July 2012,

Chomiste etal, 2011, ‘Vigorous Physical Activity, Mediating Biomarkers, and Risk of Myocardial Infarction’, Medicine & Science in Sports & Exercise, 2011 Oct;43(10), viewed 4 April 2017,

Dean C, 2012, ‘The Calcium Wars: Magnesium deficiency causes heart disease’, viewed online 4 April 2017,

Henderson M, ud, ‘Adding vitamin D to foods might be risky’. AAP Australian National News Wire, n.d., Available from: Australia/New Zealand Reference Centre, Ipswich, MA. Accessed June 24, 2012.

Nowson C, McGrath J, Ebeling P, Haikerwal A, Daly R, Sanders K, Seibel M & Mason R, 2012, ‘Vitamin D and health in adults in Australia and New Zealand: a position statement’, Med J Aust 2012; 196 (11): 686-687, viewed 17 July 2012, < >

NPS MedicineWise, 2014, ‘Vitamin D tests’, viewed 4 April 2017,

Price C, Langford J and Liporace F, 2012, ‘Essential nutrients for bone health and a review of their availability in the average North American diet’, The Open Orthopaedics Journal, 2012, 6, 143-149, viewed 4 July 2013, < >

Vorman J & Ochsenham P, 2016, The Alkaline Solution: Surviving the Modern Western Diet, Madhouse Media.

Waterhouse J , Marshall T, Fenter, B, Mangin M & Blaney G, 2011, ‘High Levels of Active 1,25-Dihydroxyvitamin D Despite Low Levels of the 25-Hydroxyvitamin D Precursor - Implications of Dysregulated Vitamin D for Diagnosis and Treatment of Chronic Disease’, viewed online19 August 2011