Tired, Achy or Worried Your Vitamin D Is Low?
Vitamin D is important for bone health, calcium absorption, normal muscle function and immune function. Low vitamin D can occur without obvious symptoms, which means guessing from how you feel is not enough.
If a blood test has shown low vitamin D, the useful question isn’t simply “Which supplement should I buy?”
It is also worth understanding your result, your individual risk factors, your diet, safe sun exposure and whether there are other reasons your vitamin D may remain low.
What Is Vitamin D Deficiency?
Vitamin D deficiency occurs when vitamin D status is below an adequate level. Vitamin D helps the body absorb calcium and supports normal bone and muscle function. Low levels can be influenced by limited sun exposure, skin pigmentation, age, diet, absorption problems and some medical conditions. Blood testing is used to assess vitamin D status.
What Does Vitamin D Do in the Body?
Vitamin D is often called the “sunshine vitamin”, but its biological role extends well beyond simply being a vitamin we obtain from sunlight.
Calcium Absorption
Vitamin D helps regulate intestinal calcium absorption and calcium metabolism.
Bone Health
Adequate vitamin D is important for normal bone mineralisation and skeletal health.
Muscle Function
Vitamin D contributes to normal muscle function.
Immune Function
Vitamin D has recognised roles in normal immune function, although supplementation should not be presented as a treatment for unrelated diseases.
What Are the Symptoms of Low Vitamin D?
One of the difficulties with vitamin D deficiency is that many people have no obvious symptoms.
Muscle Weakness
More significant vitamin D deficiency may affect muscle function and contribute to weakness.
Bone Discomfort
Significant or prolonged deficiency can affect bone mineralisation and may be associated with bone pain or tenderness.
No Obvious Symptoms
It is possible to have low vitamin D without feeling noticeably different, which is why symptoms alone cannot determine vitamin D status.
Feeling Tired Doesn’t Automatically Mean You’re Vitamin D Deficient
Fatigue has many potential causes. Iron deficiency, vitamin B12 deficiency, sleep problems, thyroid disorders, medications, stress and many medical conditions can contribute.
Rather than guessing which nutrient is low, appropriate assessment can help determine what actually needs attention.
What Causes Vitamin D Deficiency?
Low vitamin D is not always explained by diet alone.
Limited Sun Exposure
Spending little time outdoors or consistently having limited skin exposure to sunlight can affect vitamin D production.
Skin Pigmentation
People with darker skin generally require more ultraviolet exposure to produce the same amount of vitamin D as people with lighter skin.
Age
The skin’s capacity to produce vitamin D changes with age, and older adults may have increased risk of low vitamin D.
Absorption & Health Factors
Some gastrointestinal conditions, liver or kidney disorders, medications and other medical factors can influence vitamin D status.
Can You Get Enough Vitamin D From the Sun?
Sunlight exposure allows the skin to produce vitamin D, making it an important source for many Australians.
However, there is no single amount of sun exposure that is appropriate for everyone.
Vitamin D production is influenced by factors such as season, location, time of day, skin pigmentation, age, clothing and how much skin is exposed.
At the same time, Australia has a high burden of skin cancer, so advice about vitamin D should always be balanced with appropriate sun-safety guidance.
More Sun Is Not Automatically Better
You do not need to deliberately burn or expose your skin excessively in an attempt to increase vitamin D.
If you are concerned about vitamin D, appropriate testing and individual healthcare advice are safer than trying to self-prescribe excessive sun exposure.
What Foods Contain Vitamin D?
Compared with many nutrients, relatively few foods naturally contain substantial amounts of vitamin D. Food can still contribute, particularly as part of an overall balanced diet.
| Food | Examples | Nutrition Note |
|---|---|---|
| Oily fish | Salmon, sardines, mackerel | Among the better natural dietary sources of vitamin D. |
| Eggs | Egg yolk | Can contribute smaller amounts of vitamin D. |
| Fortified foods | Selected milks, plant milks and other fortified products | Vitamin D content varies, so check the nutrition information. |
| Mushrooms | Some UV-exposed mushrooms | Can provide vitamin D2, with amounts varying considerably. |
Food Alone May Not Correct a Documented Deficiency
If blood testing confirms vitamin D deficiency, simply adding a few vitamin D-containing foods may not be enough to correct it.
Your healthcare practitioner can advise whether supplementation is appropriate based on your result and individual circumstances.
Why Are Vitamin D and Calcium So Closely Connected?
Vitamin D helps regulate calcium absorption, which is why these two nutrients are frequently discussed together.
You could be eating calcium-rich foods, but vitamin D status is still one of the factors involved in calcium metabolism and bone health.
Likewise, taking vitamin D does not replace the need for adequate dietary calcium.
This is why looking at nutrient relationships rather than isolated supplements gives a more useful picture of nutrition.
Read our Calcium Deficiency & Calcium-Rich Foods Guide →Calcium + Vitamin D + Protein + Movement
Bone health is not determined by one supplement.
Adequate calcium, vitamin D, protein, resistance and weight-bearing exercise and individual hormonal and medical factors all contribute to the bigger picture.
Vitamin D, Perimenopause, Menopause & Bone Health
For women approaching and moving through menopause, vitamin D becomes part of a broader conversation about maintaining bone and muscle health.
Perimenopause
Perimenopause is a useful time to review calcium, vitamin D, protein intake, exercise and broader nutritional habits.
Explore Perimenopause Support →After Menopause
Declining oestrogen contributes to accelerated bone loss after menopause, making bone-health assessment and appropriate nutrition increasingly important.
Think Beyond One Nutrient
Vitamin D is important, but adequate calcium, protein, exercise and individual medical risk factors also need to be considered.
Explore Calcium & Bone Nutrition →Why Is Vitamin D Important for Children?
Children need adequate vitamin D and calcium for normal bone growth and development.
Vitamin D deficiency in childhood can affect normal bone mineralisation, and severe prolonged deficiency can lead to rickets.
Children with suspected deficiency, restricted diets, relevant medical conditions or other risk factors should receive appropriate assessment rather than being given high-dose supplements without guidance.
Does Your Child Have a Restricted Diet?
When children avoid multiple food groups or eat a very narrow range of foods, it can be useful to assess the whole nutritional pattern rather than focusing on one nutrient at a time.
Our clinical nutritionists support adults, children and families with practical personalised nutrition planning.
How Do You Know if Your Vitamin D Is Low?
Vitamin D status is assessed with a blood test measuring 25-hydroxyvitamin D [25(OH)D].
A blood result is much more useful than trying to determine deficiency from symptoms alone.
Your GP or healthcare practitioner can interpret your result in the context of your health history, risk factors and any supplementation you are already taking.
Where broader nutritional or functional investigation is clinically appropriate, Morkare can also help you understand which testing may actually be useful rather than ordering unnecessary tests.
Explore Functional Testing Brisbane →Test Before You Guess
Fatigue, muscle weakness and general aches can have many causes.
Testing helps distinguish a documented vitamin D problem from symptoms that may require a different investigation altogether.
Should You Take a Vitamin D Supplement?
Vitamin D supplementation can be appropriate when deficiency or increased requirements are identified, but the dose should suit the individual.
The amount needed may depend on your blood result, age, existing supplementation, medical history and other factors.
Taking more is not automatically better. Excessive vitamin D supplementation can lead to toxicity and abnormal calcium levels.
Avoid Megadosing Without Guidance
Because vitamin D is fat-soluble, excessive supplemental intake can accumulate in the body.
If you have documented deficiency, kidney disease, abnormal calcium, parathyroid problems or other relevant medical conditions, supplementation should be discussed with your healthcare practitioner.
Why Does My Vitamin D Keep Staying Low?
If vitamin D remains low despite supplementation, simply taking more without understanding why may not be the best next step.
Factors can include inadequate dosing or adherence, limited sun exposure, absorption problems, obesity, certain medications and some medical conditions.
The appropriate response depends on the individual situation and should include medical review where deficiency is persistent or unexpected.
Look for the Reason, Not Just the Number
Persistent nutritional abnormalities deserve context.
At Morkare, nutrition support can sit alongside your GP and existing medical care so dietary factors are addressed without ignoring medical causes.
Not Sure What Your Vitamin D Result Means for Your Diet?
Maybe your vitamin D keeps coming back low.
Maybe you’ve started several supplements but aren’t sure which ones you actually need.
Maybe you’ve removed dairy, changed your diet or are worried about calcium and bone health.
Or perhaps you are tired of trying to piece together conflicting nutrition advice online.
At Morkare Natural Clinic, our clinical nutritionists look at the whole nutritional picture, including your usual diet, restrictions, food preferences, existing pathology and broader health goals.
The aim is to give you a practical plan you can actually follow rather than adding another list of foods to avoid.
From Guessing to Knowing What Needs Attention
Before: seeing “low vitamin D” on a blood result, buying supplements and wondering whether your diet, calcium or other nutrients are also a problem.
After: understanding where vitamin D fits into your broader nutrition and having a clearer plan for food, lifestyle and appropriate follow-up.
Build the Bigger Nutrition Picture
Vitamin D is one piece of your nutritional health. These related Morkare resources help connect the dots.
Calcium
Understand calcium-rich foods, calcium absorption and why calcium and vitamin D work closely together.
Explore Calcium →Iron Deficiency
Explore iron deficiency symptoms, iron-rich foods and factors that affect iron absorption.
Explore Iron Deficiency →Clinical Nutrition
Bring your nutrients, food choices and health goals together with personalised nutrition support.
Explore Clinical Nutritionist Brisbane →Perimenopause
Learn more about nutrition, hormones and broader health considerations during the perimenopause transition.
Explore Perimenopause →Functional Testing
Learn how appropriate testing can sometimes help clarify nutritional and broader health questions.
Explore Functional Testing Brisbane →Vitamin D Deficiency FAQs
What are the symptoms of vitamin D deficiency?
Vitamin D deficiency may cause no obvious symptoms. More significant deficiency can affect muscle and bone health and may be associated with muscle weakness or bone discomfort. Symptoms alone cannot diagnose vitamin D deficiency.
How do I know if my vitamin D is low?
Vitamin D status is assessed using a blood test measuring 25-hydroxyvitamin D. Your healthcare practitioner can interpret the result in the context of your individual health and risk factors.
Can low vitamin D make you tired?
People with vitamin D deficiency may report fatigue, but tiredness has many potential causes. Iron deficiency, vitamin B12 deficiency, sleep problems, thyroid disorders and other medical conditions should also be considered where appropriate.
What foods contain vitamin D?
Vitamin D occurs naturally in relatively few foods. Oily fish such as salmon and sardines are useful sources, while eggs, selected fortified foods and some UV-exposed mushrooms can also contribute.
Can you get vitamin D from the sun?
Yes. Sunlight exposure enables the skin to produce vitamin D. However, vitamin D production varies according to season, location, skin pigmentation, age, clothing and other factors. Sun exposure should always be balanced with appropriate skin-cancer prevention advice.
Why are vitamin D and calcium connected?
Vitamin D helps regulate calcium absorption and metabolism. Both nutrients are important for bone health, although bone health also depends on factors such as protein intake, exercise, hormones and individual medical risk.
Is vitamin D important during menopause?
Vitamin D is part of the broader nutritional picture for bone and muscle health during and after menopause. Calcium, protein, resistance exercise and appropriate bone-health assessment also matter.
Why does my vitamin D keep staying low?
Persistent low vitamin D can have several explanations, including limited sun exposure, inadequate supplementation, absorption problems, certain medications and medical factors. Persistent deficiency should be reviewed with an appropriate healthcare practitioner.
Should everyone take a vitamin D supplement?
No. Supplement requirements vary according to vitamin D status, sun exposure, age, health history and other factors. Excessive vitamin D supplementation can be harmful, so individual advice is appropriate.
Can a clinical nutritionist help with vitamin D deficiency?
A clinical nutritionist can review your diet, food sources of vitamin D and calcium, dietary restrictions and broader nutritional adequacy. Documented vitamin D deficiency and supplementation should also be appropriately medically assessed.
Stop Guessing Which Nutrient Your Body Needs
If your vitamin D is low, your diet is restricted or you’re juggling calcium, iron and multiple supplements without knowing how everything fits together, we can help you make sense of the bigger picture.
Clinical nutrition appointments in Brisbane and Telehealth Australia-wide.
Important Health Information
This page provides general educational information and is not intended to diagnose, treat or replace medical care.
Vitamin D status should be interpreted using appropriate pathology and individual clinical assessment rather than symptoms alone.
Do not start high-dose vitamin D supplementation solely on the basis of symptoms or information on this page. Excessive vitamin D supplementation can cause toxicity and abnormal calcium levels.
People with kidney disease, abnormal calcium levels, parathyroid disorders, granulomatous conditions or other relevant medical conditions should seek individual medical advice regarding vitamin D supplementation.