Despite its nickname, many of us are not getting enough vitamin D, the essential nutrient that plays a crucial role in bone health, immune function, and overall well-being

We spoke to Helen Conway, Registered Dietitian and Nutrition Manager at FITT Meals, to uncover why vitamin D remains a common deficiency and how to boost your levels effectively.

Why is vitamin D important?

Vitamin D is a fat-soluble vitamin, meaning it’s absorbed with dietary fats and stored in the body’s fat tissue. Unlike other vitamins, it’s unique in the sense that it can be produced by the body through sunlight exposure as well as being obtained from food sources. It is widely known for supporting bone health, but its role goes far beyond just supporting your skeleton.

While vitamin D plays a critical role in helping the body absorb calcium to build and maintain strong bones and teeth, its impact goes much further. It contributes to a healthy immune system, supports muscle function, and can even play a part in reducing inflammation.

Why are vitamin D levels low in the UAE despite year-round sun?

It’s a common misconception that living in a sunny climate guarantees sufficient vitamin D. In reality, it was reported by Dubai Health Authority (DHA) that a majority of the UAE population was vitamin D deficient. This is due to a combination of factors, such as limited time spent outdoors, sunscreen use (which is essential for skin protection), modest clothing that limits skin exposure, and the natural tendency to avoid direct sunlight in extreme heat, all of which reduce the skin’s ability to synthesise vitamin D.

Additionally, people with darker skin tones need more sun exposure to produce adequate levels of vitamin D, making deficiency even more likely among the UAE’s diverse population.

What are the benefits of vitamin D?

Vitamin D is best known for preventing rickets in children and osteomalacia in adults, both of which are conditions characterised by soft, weakened bones. However, we also know that vitamin D supports muscle function, helping to reduce the risk of falls and fractures in older adults, and plays a crucial role in regulating the immune system, which in turn helps enhance the body’s ability to defend against infections.

Emerging research also suggests that low vitamin D levels may be linked to a higher risk of certain health conditions, and while further studies are needed to confirm these associations, there is broad agreement that maintaining adequate vitamin D levels is an important part of long-term health and well-being.

How much vitamin D do we need?

The amount of vitamin D you need depends on factors like age, skin tone, lifestyle, and where you live, and in the UAE, that often means thinking beyond global averages. International guidelines typically suggest a daily intake of 10–20 micrograms (400–800 IU). For example, the UK NHS recommends 10 micrograms (400 IU) daily for everyone over the age of one, while the US National Institutes of Health advises between 15–20 micrograms (600–800 IU), depending on age. Similarly, the European Food Safety Authority (EFSA) recommends 15 micrograms (600 IU) per day for healthy adults.

In the UAE, however, regional recommendations suggest a higher daily intake due to the factors mentioned above. For instance, adults over 18 years may require 25–50 micrograms (1,000–2,000 IU) daily to reach and maintain optimal vitamin D status. It is also worth noting that certain people, including pregnant women, people with darker skin, those with obesity, and older adults, may benefit from consistent supplementation at the higher end of this range, but it’s always best to consult your healthcare provider before starting any form of supplementation.

The goal is to maintain serum 25(OH)D levels between 30 and 50 ng/mL, which is considered optimal for overall health.

What influences vitamin D levels?

Vitamin D levels are affected by a range of biological and lifestyle factors that influence how much is produced in the skin or absorbed from the diet. The most significant influence is sun exposure – the body’s primary source of vitamin D. How much vitamin D your skin can produce depends on how often you’re outdoors, the season, your geographic location, and the amount of UVB light that reaches your skin.

Skin pigmentation also plays a role. People with darker skin have more melanin, which reduces the skin’s ability to synthesise vitamin D efficiently. Age is another factor – as we grow older, the skin’s capacity to produce vitamin D naturally declines, making older adults more susceptible to deficiency.

Body composition matters too. In individuals with a higher body fat percentage or elevated body mass index (BMI), more vitamin D tends to be stored in fat tissue, which can reduce the amount available for the body to circulate and use effectively. Finally, digestive and liver health can influence vitamin D levels. Conditions that impair fat absorption (such as coeliac or inflammatory bowel disease) or affect liver function can interfere with the activation and utilisation of vitamin D.

Can you have too much vitamin D?

Yes, although it’s rare and usually due to excessive supplementation. Since vitamin D can be stored in the body, very high intakes over time can lead to vitamin D toxicity, causing elevated calcium levels (hypercalcemia), which may result in nausea, kidney stones, or soft tissue calcification. The upper safe limit for adults is set at 100 micrograms (4,000 IU) per day by both the European Food Safety Authority (EFSA) and the National Institutes of Health (NIH).

What are the signs of vitamin D deficiency?

Most people with vitamin D deficiency have no obvious symptoms, especially in the early stages. Deficiency often goes unnoticed until it’s picked up through routine blood tests or when more serious complications begin to emerge. When symptoms do appear, they tend to

be subtle and can develop gradually, meaning they’re easy to dismiss. Some of these include fatigue or low energy, muscle weakness, lingering aches, or an unexplained soreness in the lower back or legs, which may indicate low levels of vitamin D. Some people become more prone to fractures or find that their bones take longer to heal after an injury. Others notice they’re getting respiratory infections more often than usual.

In cases of severe or prolonged deficiency, children may develop rickets, and adults may experience osteomalacia. These conditions are linked to impaired bone mineralisation, which is the process by which minerals like calcium are deposited into the bone to keep it strong and structurally healthy.

What are the best dietary sources of vitamin D?

Vitamin D is found naturally in only a small number of foods, so including these sources in your diet or choosing fortified products can play an important role in maintaining healthy levels. Oily fish such as salmon, mackerel, trout and sardines top the list, offering some of the richest natural sources of vitamin D. Fish liver oils are also among the richest natural sources. Egg yolks and liver, particularly beef liver, can also contribute small amounts to your overall intake. Fortified foods (where vitamin D has been added), including many dairy and plant-based milks, breakfast cereals, and margarines, are perhaps one of the easiest sources. Even mushrooms can help, but only if they’ve been exposed to UV light.

Since it’s difficult to meet requirements through food alone, supplementation is often necessary, particularly in populations with limited sun exposure.

If you’re unsure about your vitamin D status, a simple blood test can provide clarity, and your healthcare provider can help advise you on the right dosage, whether from food, supplements, or both. For many of us in the UAE, adding a small supplement could make a big difference in long-term health.

All health content on bbcgoodfoodme.com is provided for general information only, and should not be treated as a substitute for the medical advice of your own doctor or any other health care professional. If you have any concerns about your general health, you should contact your local health care provider.