COLUMN: Know your vitamins – here’s everything you need to know about vitamin D


Many nutrients, vitamins and minerals are needed to maintain our health, but Vitamin D is truly versatile as it is required for many bodily processes and has enormous benefits in both preventing and treating disease.

Here, nutritionist Laurann O’Reilly and owner of Nutrition by Laurann, explains everything you need to know about vitamin D.

What is Vitamin D?

Vitamin D is an essential and essential nutrient for the normal development and function of many organs in the body and for the maintenance of optimal health throughout our lives.

Where can we get this?

We make vitamin D by exposure to sunlight via our skin, specifically ultraviolet B (UVB) rays, which is why it is also known as the “sunshine vitamin”.

The World Health Organization’s advice is to get 5 to 15 minutes of occasional sun exposure for your hands, face and arms two to three times a week during the summer months.

However, during the fall and winter months, the sun is not strong enough for us to make vitamin D. We must get our vitamin D from our diet (HSE).

It can be found in small amounts of food products containing vitamin D2 (ergocalciferol) found in some herbal products and vitamin D3 (cholecalciferol) found in some animal products.

However, the richest food sources are found in fortified foods.

As it is often difficult for people to get enough vitamin D from food alone, the HSE recommends taking a daily vitamin D supplement during autumn and winter.

What are the benefits?

Although vitamin D has many benefits, here are some of the few

– Healthy bones and teeth – Vitamin D is essential for strong bones as it is needed for the absorption of calcium and phosphorus from food. These are two essential minerals for maintaining healthy teeth and bones while helping to prevent osteoporosis.

– Support the immune system – Evidence suggests that vitamin D may have an important and supportive role for the immune system, particularly in regulating the immune response and reducing proteins known to trigger inflammation.

– Improve Gut Health – A study last year found that vitamin D supplementation can significantly increase the variety of our gut bacteria, which play an important role in digestion, immunity and hormonal balance .

– Mood – As our body produces vitamin D from sunlight, our levels of this vitamin can seriously decrease during the dark winter months. It has also been suggested that this drop in vitamin D may be linked to “seasonal affective disorder” or SAD, a mood disorder that is also common in individuals during this time. Indeed, vitamin D is involved in the regulation of serotonin production.

The Irish TILDA study also found that people over 50 are 75% more likely to suffer from depression if their vitamin D levels are low.

– Respiratory Health – Vitamin D is known to help fight bacteria and viruses and reduce acute respiratory infections.
An international study (the Jolliffe papers) showed “a 25% reduction in the risk of respiratory infections in those who take a daily vitamin D supplement”.

– Potential use with Covid-19 – Most of us have by now heard of the Oireachtas report published last year which discusses the potential role of vitamin D in “preventing health problems and respiratory diseases” and how “Vitamin D is known to help the immune system in the fight against harmful bacteria and viruses” as well as “reducing the risk of acute respiratory (lung) infection”. Based on this report, they recommended that everyone in Ireland takes a vitamin D supplement.

What affects our vitamin D levels?

Skin Pigmentation – People with darker skin are at a higher risk of having low vitamin D due to a higher level of melanin in their skin. Unfortunately, melanin reduces the ability of UVB rays to pass through the skin, reducing the body’s ability to make vitamin D.

Age – As we age, our body’s ability to produce vitamin D from the sun becomes less efficient due to the effect of the aging process on the skin.

A study comparing the amount of vitamin D3 produced in the skin of 8- and 18-year-old subjects with the amount produced in the skin of 77- and 82-year-old subjects found that the younger group had more than twice the ability to produce vitamin D3. D.

The season – In Ireland we have reduced the hours of sunshine from autumn to mid-spring, which limits our opportunities to create vitamin D.

Other factors that can limit our exposure to the sun are long hours of working or studying indoors as well as lack of opportunities to access the outdoors, such as nursing home residents and those who do not have a safe outdoor recreation area.

Clothing – As we need our skin to be exposed to the sun to create vitamin D and Ireland is rarely warm enough to live without a sweater, jacket or scarf, this reduces again the chances of creating the vitamin.

Sun protection – It is very important to be careful when exposing the skin to the sun to prevent skin cancer.

The correct application of a product containing an SPF of 15 has been shown to almost completely prevent the cutaneous production of

Vitamin D, which is why adequate food sources and supplementation are important.


In addition to not getting enough sunshine in Ireland, the quality of sunshine generally does not provide enough UVB to generate enough vitamin D, especially in the winter months to support our immune system.

The recent Oireachtas report explained how deficiency can be found in all age groups, with deficiency found in nearly half of 18-39 year olds, over a third of 50-59 year olds, 64% of older age 80, 67% resident nursing home and 93% from BAME (Black, Asian and Ethnic Minority) communities.

Recommendation: The Oireachtas report published last year recommends that the general Irish adult population take a supplement of 20-25 μg/day or 800-1000 IU/day, while children should take 10 μg or 400 IU /day as a public health measure. aim to reduce the risk of respiratory diseases and other diseases such as osteoporosis.

Note: If you have any pre-existing medical conditions, taking medication, infants and young children, please consult your GP or pharmacist first.

Dietary sources: Vitamin D can be found in fatty fish such as mackerel, sardines, canned salmon, kippers and herring and a small amount in sources such as red meat, liver and eggs.

Fortified milk like super milk and cereals are also great sources.

The Oireachtas report suggests that the supplement recommendation above be taken alongside dietary sources to adequately meet needs.

Supplements: The report also discusses the importance of vitamin D supplementation not only for the adult Irish population, but also for vulnerable groups such as those in nursing homes and healthcare workers.

Vitamin D supplements usually come in the form of a spray or capsule. When choosing a vitamin D supplement, it is best to choose vitamin D3, which is the most effective form of the vitamin and is also the most effective in improving blood vitamin D. levels.

Supplement Recommendations: My favorite vitamin D supplements are PharmaNord BioActive Vitamin D Pearls (available in 38 μg/1520 and stronger 75 μg/3000 IU), PharmaNord BioActive Junior Vitamin D Pearls 5 mcg/200 IU ( suitable for children over 2) and Shield Health BabyVitD3 5 mcg/200 IU Drops (suitable from birth).

Note: For infants or young children, please consult your pharmacist or GP first.

Vitamin D Boosting Recipe
Baked Teriyaki salmon with brown rice
(For 4 people)
1 Salmon Steak = 292 IU of Vitamin D

4 salmon steaks
1 sliced ​​onion
1 tablespoon sesame seeds
Boil brown rice in the bag
Teriyaki sauce:
⅓ cup low sodium soy sauce
¼ cup fresh orange juice
2-3 tablespoons of water
2 tablespoons of honey
2 minced garlic cloves
1 tablespoon chopped fresh ginger
1 tsp chili flakes or to taste (option if you like a spicy kick)
½ lemon juice
½ tablespoon plain flour

Preheat the oven to 200° Celsius
In a small bowl, whisk together all the ingredients for the teriyaki sauce
Spray a baking dish with nonstick cooking spray and place the salmon and onions in the dish.
Pour sauce over then bake in preheated oven for 12-15 minutes until cooked through and flaky
While the salmon cooks, boil the rice following the cooking instructions on the box (this should take about 10 minutes)
Once the salmon is cooked, remove from the oven and pour over the remaining sauce in the baking dish.
Serve on a bed of your prepared brown rice
Sprinkle with sesame seeds and enjoy!


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