How Much Vitamin D Should I Take?

With the darker and colder days slowly approaching, it’s important to consider supplementation with vitamins that are important to be consumed this time of the year. Vitamin D is one of them.

Vitamin D deficiency is prevalent worldwide but occurs at higher rates in specific populations. Vitamin D is an essential vitamin, and almost every cell in your body has a receptor for it. It’s produced in the skin, but only when it’s exposed to sunlight.

The main dietary sources of vitamin D are fish liver oils and fatty fish – but even if you consume foods high in Vit D, deficiency can happen for people who don’t get enough sunlight (like us in Ireland). For these individuals vitamin D supplements are essential.

Vitamin D is important for bone health and has also been linked to overall immune function and protection.

Daily Dosage

A daily Vitamin D intake of 1,000–4,000 IU should be enough to ensure optimal blood levels for most people. Generally speaking, it’s not recommended to exceed the upper limit of safe intake, which is 4,000 IU per day.

There are many different vitamin D supplements in the market with different presentations – capsules, tablets, and liquid - and different concentrations – ranging between 1,000IU and 10,000IU. Higher doses of vitamin D should only be taken every 3-4 days, and after consulting with your GP or dietitian.

How much vitamin D is too much?

Since relatively little is known about how vitamin D toxicity works, it’s hard to define an exact threshold for safe or toxic vitamin D intake.

According to the National Academy of Medicine, 4,000 IU is the safe upper level of daily vitamin D intake. However, doses up to 10,000 IU have not been shown to cause toxicity in healthy individuals, in individuals with vitamin D deficiency, and in individuals that took the dose every 3-4 days.

Although vitamin D toxicity is a very rare condition, it can happen when large doses are taken daily, and with the recent increases in supplement use, it’s important to keep this in mind. Always speak to your GP or a healthcare professional before starting on any supplements.