Vitamin D Deficiency, Signs & What to Look For

Vitamin D - Title
Author: Craig Stewart
Date Published: 12th May, 2022
Time to Read: 5-7 minutes
Vitamin D Deficiency - BLOG Header Image

Vitamin D is a vitamin and like all of the vitamins, is essential for human health.

Vitamin D differs from of the other vitamins because it is made through a chemical reaction in the skin. This chemical reaction is triggered through exposing the skin to UVB radiation from sunlight, for this reason it is often referred to as the sunshine vitamin.

Getting enough vitamin D is crucial for healthy bones and teeth, this is because the active form of vitamin D, made in the kidneys, plays an important role in the regulation of calcium and phosphorus.

In children, being deficient in vitamin D can result in rickets, where the bones are weak, soft and can become deformed (with bow legs).

In adults, low blood levels of vitamin D increase the risk of osteoporosis, or thinning of the bones. This can put you at an increased risk of falls and bone fractures.

Vitamin D is important for much more than just bone health. More recent research now shows that Vitamin D may play a role in:

  • Improving muscle strength.
  • Maintaining a strong immune system, helping to fight off infections.
  • Protecting you against certain types of cancer.
  • Reducing your risk of falls.
  • Helping to stave off depression and low mood.
  • Keeping your energy levels up.

There is increasing evidence to support vitamin D playing a role in immune system modulation and for its anti-inflammatory properties.

What Are The Symptoms Of Vitamin D Deficiency?

Vitamin D Deficiency Symptoms in Babies and Infants

Babies with severe vitamin D deficiency may get cramps, seizures, arrhythmia's and stridor (breathing difficulties). These problems are related to hypocalcaemia, low levels of calcium.

Vitamin D Deficiency Symptoms in Children

Children with severe deficiency may have soft skull or leg bones. Their legs may look curved. This condition is known as rickets. They may also complain of bone and muscle soreness or general weakness and fatigue.

  • Poor growth. Height is usually affected more than weight.
  • Tooth delay. Children with vitamin D deficiency may be late teething.
  • Children with vitamin D deficiency are more prone to infections.
  • When rickets is very severe, it can cause low levels of calcium in the blood. This can lead to muscle cramps, fits and breathing difficulties.
  • Severe vitamin D deficiency can cause weakness of the heart muscle (cardiomyopathy).

In respect of respiratory type infections, study results have been largely mixed about vitamin D and flu prevention however this randomized trial of school aged children found those children who took vitamin D as part of the intervention group were 42 percent less likely to contract the seasonal flu compared to those that received a placebo.

Vitamin D Deficiency Symptoms in Adults

Some people with vitamin D deficiency complain of a general feeling of tiredness, aches, pains and an overall sense of not being well.

In severe cases of vitamin D deficiency there may be more noticeably severe pain and muscle weakness. Muscle weakness may cause difficulty in climbing stairs, getting up from a low position or restricting general day to day activities.

Bones may feel painful to moderately applied pressure (often more noticeable in the ribs or shin bones – check out our free at home screening test here). Bone pain may also occur in the back, hips, pelvis, legs and feet.

Vitamin D deficiency may also cause changes in mood and play a role in certain conditions like seasonal affective disorder (SAD) and depression.

In this 2014 meta-analysis the authors suggest vitamin D supplements may in some cases be as effective as antidepressant medication and call for more research.

“The effect size for Vitamin D in depression demonstrated in this meta-analysis is comparable with the effect of anti-depressant medication, an accepted treatment for depression. Should these results be verified by future research, these findings may have important clinical and public health implications.”

Is Vitamin D Deficiency Serious?

Vitamin D deficiency is a serious condition and should be treated by your primary care physician or family Doctor.

Treatment is generally safe, effective and in New Zealand, Vitamin D3, commonly referred to as cholecalciferol, is available as a subsidized prescription medication.

If left untreated over time, vitamin D deficiency may lead to serious bone disorders. For example, chronic, severe and long-term vitamin D deficiency may result in rickets or osteomalacia.

Moreover, low vitamin D status is shown to be associated with many autoimmune conditions, diseases and some cancers however more research is required to elucidate whether this relationship is correlative or causative.

What Happens When Your Vitamin D Level Is Low?

Most people will experience no vitamin D deficiency symptoms or may only complain or be aware of mild symptoms such as tiredness or general aches and pains.

Vitamin D deficiency can lead to a loss of bone density, which can contribute to osteoporosis and broken bones.

Severe vitamin D deficiency may also lead to other diseases.

Because the symptoms of vitamin D deficiency can be nonspecific, vitamin D deficiency is often missed and undiagnosed.

Diagnosis of vitamin D deficiency is more likely in at risk groups with some of the classical symptoms such as rickets or osteoporosis.

In New Zealand, those most at risk for vitamin D deficiency are:

  • If you are over 65+.
  • If you’ve had a hip fracture.
  • If you have darker skin colour.
  • If you don't spend a lot of time outdoors.
  • Breastfed Infants (if mother is deficient).
  • If you are obese or overweight.
  • If you take specific medicines.
  • If you have a malabsorption condition.

Testing for vitamin D is considered expensive, often not subsidized and in most cases is not considered necessary, attitudes and health policies that may possibly contribute to the vitamin D deficiency and insufficiency we now see in general populations around the world.

In New Zealand, according to this 2008/09 New Zealand Adult Nutrition Survey, more than 25% of the New Zealand population had insufficient blood levels of vitamin D based on New Zealand guidelines.

The mean level of vitamin D in the New Zealand population was 63.6 nmol/L (25.44ng/ml) for men and 62.4 nmol/L (24.96ng/ml) for women; below the 75nmol/L (30ng/ml) blood level for vitamin D the Endocrine Society now suggests as a minimum for vitamin D sufficiency.

Attitudes are changing with the most recent survey of New Zealand Doctors regarding their views in respect of vitamin D importance suggests 87% of family Doctors whom participated in the survey agreed with the statement that they were concerned their patients may not be getting enough Vitamin D.

How Can I Increase My Vitamin D Level?

Based on the most recent information available in New Zealand, and in-line with international trends, vitamin D deficiency and insufficiency is common.

More than one in every four New Zealanders have insufficient blood levels of vitamin D.

Vitamin D insufficiency may even be more common than this when clinical guidelines for vitamin D are reviewed against the Endocrine Society's Guidelines for Vitamin D which are set higher than guidelines in New Zealand, summarized in the below table.


Most people are unable to achieve a vitamin D level in the upper range for sufficiency as recommended by the Endocrine Society through sun exposure alone. Many factors may influence this from where we live, lifestyles as well as sun exposure and sun avoidance behaviors.

The only way to tell if you have a sufficient blood level of vitamin D is to test your vitamin D level.

Testing for vitamin D is easy and now readily available to New Zealand in the form of vitamin D test kits or patients may self refer and pay for a vitamin D test at a pathology clinic near them.

From there, determine a dose of vitamin D to achieve your desired target level, and choose either a regular daily maintenance dose or discuss with your Doctor about starting an initial “loading” or bolus dose to help bump any concerning levels up more quickly.

Whilst supplementation of vitamin D is generally safe, easy and well tolerated, it is always recommended that you discuss your intended supplementation regimen with your primary care physician.