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  • HuskNutrition

Why Vitamin D?

Vitamin D is incredibly important as it supports many areas of your health.

It's important to take vitamin D as you may have been indoors more than usual this year.

Obviously known for its role in supporting the immune system but also for teeth, bones and muscles as it helps the body regulate calcium and phosphate.

Vitamin D is also important for healthy cell division – a vital function in the human body and especially for children and pregnant women.

In the UK it is recommended that adults and children over the age of 4 should consider taking a vitamin D supplement in Autumn and Winter (October-March) when the sun is not strong enough for your body to make vitamin D in response to sunlight.

Vitamin D deficiency has also been implicated in inflammatory conditions such as Crohn’s Disease and Rheumatoid Arthritis.

There are reports that taking vitamin D close to bedtime may interrupt sleep patterns so its more natural cycle would be to take it in the morning.

It’s important to see sunlight for many reasons:

Vitamin D is made in the body as a natural response to sunlight. Typically 90% of your vitamin D comes from this and only 10% from food. Depending on where you live and your heritage, vitamin D needs will vary. If you’re in Spain with plenty of sun 20-40 minutes of light will meet ‘basic requirements’ (but remember we’re about thriving not surviving), whereas if your heritage is of black origin (and melanin is higher), you will find it very difficult to get enough if you’re living in Scandinavia…

The importance isn’t just in the balance of nutrients but mores important in the reaction of hormones and cell expression.

Sunlight also helps convert factors in steroid hormone synthesis. Thyroid, progesterone, oestrogen, DHEA, cortisol, testosterone… which also improve your sense of wellbeing and health.

Sunlight also triggers mitochondria (your cells little powerhouses!) to produce energy, getting you up in a morning and going about your day… why do people get sickest and injured in winter and especially near xmas (darkest nights)? No light, lower metabolism, altered nutrient needs, cells expression of energy is lower…

So we add dietary support to the liver, the kidneys, the transport of nutrients across cells, try and get sunlight in the day and keep our mitochondria as active as possible.

In the UK, adequate exposure to sunlight is important, especially between April and October. Public Health England recommends vitamin D supplements are taken by people in at risk groups (for example, women who are pregnant or breast-feeding, young children and those with osteoporosis.

Vitamin D acts within the body much like a hormone rather than a vitamin. It is required to absorb calcium from for food, via the gut into the bloodstream.

What if I don’t get enough?

Vitamin D deficiency is common in the UK, probably due to our work schedules and lack of sun exposure. If you have severely low vitamin D levels you are unable to maintain an adequate concentration of calcium in your blood for bone growth which may cause rickets and osteocyte formations…

As the role of vitamin D as a regulator of other functions has emerged, it has been suggested that a lack of vitamin D is linked to an inability to fight infections (COVID-19 being a primary concern currently), muscle weakness, fatigue and the development of diabetes, amongst other major issues.

You may not absorb vitamin D if you have issues with fatty acid malabsorption (pale and yellow stools), are on certain medications, such as weight loss drugs like orlistat (fat binders), corticosteroids and phenyl-esters.

What happens if I have too much vitamin D?

It is very rare to have too much vitamin D if you’re not supplementing your diet. If your vitamin D levels are too high over a significant time period this may cause too much calcium to build up in the body which can result in weakened bones, and damage to the kidneys and the heart.

Therefore, it is important to regularly get your vitamin D levels tested when taking high strength vitamin D supplements.

Foods that are rich in vitamin D:

Cod Liver/Offal/Fish Oil - as animals utilise vitamin D in the livers and kidneys we find high levels here. Vitamin D is stored in our fat cells and remains inactive until needed.

Mushrooms - crimini’s, portabella and shitake/maitake are highest, typically grown in under UV light which enhances the level of vitamin D.

Eggs - found in the yolks - eat them whole and if you can, as raw in the centre as you like.

Fish especially trout and salmon - again - these animals are in sunlight and preserve vitamin D in the fatty stores.

Fortified foods - (orange juice, plant based’ dairies’ such as oat and almond milk or butters etc) these are typically more processed and multivitamins and minerals are added at a later stage - which may or may not be present in the original whole food. Importantly here though: are a non-animal sources of D3.

For best absorption you want to take it with fat (as it is fat soluble), calcium, deep greens such as spirulina, coriander, spinach or kale for K2 and fibre.

Vitamin D being fat soluble you will notice a trend in the above foods being predominantly animal sources. Proteins have natural fats (nature usually provides protein and fat together) with the rest of their macronutrients which too are more bioavailable.

Taken from the NHS website as a safe recommendation:

‘You should take 10 micrograms (400 IU) of vitamin D a day between October and early March to keep your bones and muscles healthy.

There have been some reports about vitamin D reducing the risk of coronavirus (COVID-19). But there is currently not enough evidence to support taking vitamin D to prevent or treat coronavirus.

From about late March/early April to the end of September, the majority of people should be able to get all the vitamin D they need from sunlight on their skin.

A microgram is 1,000 times smaller than a milligram (mg). The word microgram is sometimes written with the Greek symbol μ followed by the letter g (μg).

Sometimes the amount of vitamin D is expressed as International Units (IU). 1 microgram of vitamin D is equal to 40 IU. So 10 micrograms of vitamin D is equal to 400 IU.’ - (accessed 12th December 2020)


Read Public Health England’s Vitamin D report here:

Great article on the raypeatforum discussing sunlight’s benefit to life:

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