7 Benefits of Vitamin D & How to Boost Your Levels

Aug 27, 2023 | Eating Right

Vitamin D is currently in the headlines, as a new Australian study suggests it can reduce heart attack risk

It’s not the only reason that vitamin D is essential, though. There are plenty of great reasons to top up your Vitamin D levels! 

Often referred to as the “sunshine vitamin,” Vitamin D is a unique micronutrient. Our bodies can naturally synthesise vitamin D with exposure to UV rays, but foods high in vitamin D also help to maintain healthy levels, especially in winter.

Despite Australia’s reputation as a sun-drenched country, Vitamin D deficiency is incredibly common, affecting 1 in 3 adults. Anyone with low sun exposure is especially at risk, including older Australians.

In this blog post, I’ll explore:

  • Why vitamin D is important 
  • What it does for the body
  • Symptoms of vitamin D deficiency
  • How to get enough vitamin D

I’ll give you my best tips for getting more vitamin D, including dietary sources and the best time of day to get sunlight for vitamin D production. 

Read on for everything you need to know!

What is Vitamin D?

Vitamin D (calciferol) is a group of fat-soluble hormones that play a significant role in bone health and metabolism. While we call it a vitamin, it’s different to other nutrients in that category – especially as most people naturally generate vitamin D in response to sunlight exposure.

Sun exposure is the biggest (and most efficient) way to satisfy our vitamin D needs. However, we can also get vitamin D from our diet or supplementation (if necessary). 

Vitamin D also needs to go through two enzymatic processes in our body to activate it: first in the liver and then in the kidneys. The active form of vitamin D is called calcitriol, which acts like a steroid hormone. 

Calcitriol isn’t the kind of steroid that makes you ‘buff’ but is essential for bone and muscle health!

Read on to learn more about the role of vitamin D in the body. 

Why is Vitamin D Important? 7 Benefits for Health

Vitamin D receptors (VDR) are found in most cells in the body. It’s essential for cell growth, metabolism, immune function, and many more processes. 

Let’s take a closer look at the health benefits of vitamin D:

1. Strong Bones 

Vitamin D’s most essential role is building strong, healthy bones. The hormone calcitriol balances our calcium and phosphorus levels, ensuring we absorb what we need from our diet. These minerals are critical for bone formation, as well as nerve health. 

Without enough Vitamin D, the body takes calcium from bones, causing them to become  weaker and brittle. Over time, this can cause fractures and chronic bone diseases, like osteomalacia or osteoporosis in adults and rickets in children. 

2. Heart Health

Vitamin D plays a role in keeping the cardiovascular system healthy. People with vitamin D deficiency are more likely to suffer from high blood pressure or heart disease.

New research in Australia showed over-60s taking vitamin D supplements had a 9% lower rate of major cardiovascular events and a 19% lower incidence of heart attack.

Past studies suggest that vitamin D levels indirectly affect blood pressure, helping manage heart disease risk. 

While a low level of Vitamin D doesn’t cause heart conditions, it’s clear there is a link between the two. If you have a vitamin D deficiency, restoring your blood serum levels is a helpful step to manage your risk.

3. Active Immune System 

Vitamin D plays a critical role in supporting the immune system. Having adequate vitamin D levels increases your ability to fight infections. For example, studies show vitamin D reduces the severity of Covid-19 symptoms, decreasing mortality rates and the need for ICU treatment. 

Note that vitamin D itself doesn’t treat or cure illness – but inadequate vitamin D levels hamper the body’s immune response. Restoring vitamin D levels supports the body’s ability to tackle viruses and bacteria.

It helps regulate immune responses, reducing the risk of autoimmune disorders and boosting overall immune function.

4. Manages Inflammation

Vitamin D helps regulate inflammation levels in the body. Over time, chronic inflammation can be damaging to our cells and organs. 

Studies have shown a connection between inflammation and low vitamin D levels. Patients with vitamin D deficiency were more likely to have high C-reactive protein levels (CRP) – one of the biomarkers of inflammation.

Chronic inflammation is linked to heart disease, Alzheimer’s, diabetes, weight gain, and other diseases. Vitamin D helps regulate the immune system, avoiding a systemic inflammatory response. 

If you’re following an anti-inflammatory diet, it’s ideal to include sources of vitamin D, like oily fish.  

5. Mood Regulation 

Emerging research suggests a connection between vitamin D levels and mental health. Adequate vitamin D intake may manage symptoms of depression, anxiety, and other mood disorders.

Vitamin D supplementation can be a proactive step against conditions such as Seasonal Affective Disorder (SAD), especially if you live in parts of the world with extended periods of darkness.

As a bonus, some of the best mood-boosting foods contain vitamin D – a great way to support your mental health through nutrition. 

6. Manages Risk of Diabetes

Vitamin D positively affects insulin sensitivity, which helps manage type 2 diabetes symptoms. Insulin resistance is associated with metabolic syndrome, leading to risk factors for cardiovascular health and other conditions. 

A study at the University of Copenhagen found that supplementing with vitamin D reduced blood glucose levels in patients with type 2 diabetes. They concluded that vitamin D supplementation could be an effective way to reduce diabetes risk.

7. Reduces Menopausal Symptoms 

Vitamin D is vital for women during perimenopause and menopause. First of all, the decline in oestrogen during this time increases the risk of osteoporosis. Vitamin D is critical to getting enough calcium from food or supplements, so be sure to check your levels to avoid bone loss. 

Low vitamin D levels are also linked to more severe menopausal symptoms, such as hot flashes and mood swings. In conjunction with other treatments, like exercise and hormone therapy, getting enough vitamin D and other essential nutrients helps manage menopause symptoms.

How Much Vitamin D Do I Need?

The recommended daily vitamin D intake varies depending on age, sex, lifestyle and overall health. One major factor is whether you get enough sunlight during the day.

The Australian government recommends the following daily Vitamin D intake:

  • 0 to 50 years: 5μg (micrograms) or 200 IU
  • 51 to 70 years: 10μg (micrograms) or 400 IU
  • Over 70 years: 15μg (micrograms) or 600 IU

You may also need more than the standard five micrograms if:

  • You have minimal sun exposure, or
  • You have a diagnosed vitamin D deficiency

If you spend your days inside or need to cover your skin outdoors, you’re at higher risk of vitamin D deficiency. 

Please note that these are general guidelines. The best way to determine how much vitamin D you need is to speak to your GP or nutritionist. 

Symptoms of Vitamin D Deficiency

Common symptoms of vitamin D deficiency include:

Long-term vitamin D deficiency can contribute to the development of osteoporosis, a condition characterised by weak and brittle bones, and increase the risk of falls and fractures, especially in older adults.

Sources of Vitamin D

Very few foods contain vitamin D, and the primary natural source is synthesis via the skin. We naturally generate most of our vitamin D with adequate sun exposure – specifically, UVB rays.

Let’s unpack the three sources of vitamin D:

  • Sunlight: The most natural and effective way to obtain vitamin D is through direct exposure to sunlight. Spending around 15-30 minutes in the sun, with arms and legs exposed a few times a week, can help your body produce adequate amounts of vitamin D.
  • Food Sources: While less abundant, certain foods contain vitamin D naturally or are fortified with it. Fatty fish such as salmon, mackerel, and sardines are excellent sources.
  • Supplements: If sunlight is limited or dietary sources are insufficient, vitamin D supplements are available. It is important to consult your GP or nutritionist to determine the correct dosage before taking supplements.

Learn More: 18 Foods High in Vitamin D (List + Healthy Recipes)

How to Get Vitamin D from Sunlight

To ensure your vitamin D stores are topped up and maintained as the seasons change, here’s what you need to do:

Aim for a minimum of 15 minutes of sunlight between 10 am and 3 pm. This is when UVB rays are present in the greatest amount – so if you jog or exercise early in the morning, it may not be the ideal time for vitamin D production.

You can check the Australian sunshine map to find out how many minutes of sunlight you need in your location. A general rule of thumb is to check your shadow. When it is much shorter than you, the sun’s rays enter the atmosphere at the correct angle for your skin to utilise the UVB rays.

In winter, you will notice that your shadow is much longer for most of the day, and this is when no amount of sun will be beneficial.

Optimal absorption will take place with minimal clothing and sun cream. Don’t go over the top with ‘Slip, Slop, Slap’ (unless you have a family history of skin cancer). While I’m all for caring for your skin, the right amount of natural sunlight is vital for vitamin D synthesis. Especially in winter, exposed skin is important to make sure you get enough UVB. 

Please ensure you factor in your current skin tone and avoid getting burnt. If you have very fair skin and a history of minimal sun exposure, please start with 5 minutes per day and increase your duration over three to four weeks.

Vitamin D Supplements: Do I Need Them? 

You might require vitamin D supplements if:

  • you can’t get enough sun exposure (especially in winter)
  • you have a darker skin tone 
  • you’re over 50 (as vitamin D synthesis reduces with age)
  • your BMI is over 30

A three-monthly blood test will determine if you need vitamin D supplements and your required dosage. Ideally, monitor your levels every three months with follow-up testing. Optimum levels are greater than 75 nmol/L.

Vitamin D supplements come in two forms – D2 and D3. Both are effective, but D3 is more beneficial. It’s the form that the body naturally produces when exposed to sunlight and tends to elevate blood serum levels for longer. 

When deciding which supplements you need, it’s important to consult a GP, nutritionist or naturopath. Many supplements won’t help if you don’t have a deficiency, so it’s easy to throw money away. 

I always recommend practitioner-grade supplements from a nutritionist or naturopath over picking up something off the shelf. These are much higher quality, and you can also get advice on your ideal dosage. 

Is It Possible to Get Too Much Vitamin D?

Yes, it is possible to ‘overdose’ on vitamin D, but it’s very rare. This condition is known as vitamin D toxicity or hypervitaminosis D usually happens if you take high-dose vitamin D supplements for a long time, not from diet or sun exposure.

The main consequence of vitamin D toxicity is a build-up of calcium in your blood (hypercalcemia), which can cause symptoms such as nausea, vomiting, weakness, and frequent urination. More severe complications can include kidney damage, heart rhythm problems, and bone loss.

The tolerable upper limit of vitamin D is 4,000 IU/day for most adults. However, you won’t benefit from taking extra vitamin D if your levels are sufficient, so there’s no need to take this much! 

If you’re considering taking vitamin D supplements, your doctor or nutritionist can advise you on the right dosage for your needs.

Key Takeaways

Vitamin D is critically important for our overall health and well-being. From bone health to immune function, it impacts every part of our holistic health.

Not only that, but research shows it has a role in preventing chronic disease. Low vitamin D is a risk factor for diabetes, high blood pressure, heart disease and more.

Supplements can provide a solution, but good old-fashioned sunlight is the best way to get vitamin D. If you’re struggling, ensure your vitamin D levels are tested before taking any supplements.

Between sunlight, diet, and supplements when necessary, there are plenty of ways to get your ‘sunshine vitamin’ fix!


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