Vitamin D3 with Coconut Oil from Natural Stacks provides you with this essential vitamin, which is deficient in large percentages of the population, in a highly bioavailable form. Vitamin D3 is only present in small amounts in the diet. Theoretically humans are capable of synthesising the vitamin that they need in their skin. However the synthesis requires energy from ultra violet B rays in sunlight. Because of less time spent out doors, and because most people now use sunscreen lotion whenever they are out in the sun, it is estimated that a large percentage of the population is not getting enough sun to make sufficient amounts of the vitamin. This comes at the same time as new roles for the vitamin are discovered. It is increasingly being recognised that a vitamin D3 supplement will benefit most people. Since the vitamin is involved in higher brain function, mood stabilisation and protecting the brain from effects of aging, many people see a boost to their cognition and mood when they start supplementing the vitamin.

Each softgel of Natural Stacks’ vitamin D3 with Coconut Oil contains 10x the recommended daily amount of the vitamin (which many nutritionists consider to be too conservative). The vitamin present is in the form of Cholecalciferol, which is easier to absorb and has higher bioavailability than other forms. The fat soluble vitamin is packaged with 100 mg of coconut oil, arguably the healthiest oil there is, to improve absorption from the digestive tract.

Vitamin D3 Synthesis

Vitamin D is actually several different sterol molecules. Vitamin D3 (Cholecalciferol) is the form that can be synthesised in the skin through the action of ultraviolet B rays present in sunlight on 7-dehydrocholesterol. It is estimated that in healthy humans 90% of vitamin D in the body is synthesised in this way, with only 10% coming from the diet, mostly from oily fish or eggs. However evidence is also accumulating that people are not getting enough exposure to sunlight to produce sufficient amounts of the vitamin. This is especially true of people living in countries, such as the UK, with limited sunlight and very short days during the winter. The amount of sunlight that is needed to produce sufficient vitamin D depends on the amount of melanin in the skin. Pale people require less exposure than people with dark skins. Pilot studies in Britain suggest that as much as half the white population is vitamin D deficient, and as much as 90% of the multi-ethnic population.

Even in a country blessed with sunny weather such as Australia, a third of the under 25 population is deficient in vitamin D. It is probable that the advice to avoid excessive sunbathing, to prevent skin cancer, and the widespread use of sunblock lotions play a major role in the increasing vitamin D deficiency.  Even a low SPF factor sunscreen lotion drastically reduces the amount of vitamin D that can be synthesised in the skin. There is also a general decrease in time people, and especially children, spend outside. Glass does not let UV light through, hence exposure to sunlight inside is not much use in terms of producing the vitamin.

The Functions of Vitamin D

For many years the only function of vitamin D that was known was the absorption of calcium and phosphate from the diet and the deposition of these minerals in bones. The lack of vitamin D in childhood caused the disease rickets, which was characterised by weak soft bones and resulted in ‘bow legs’, since the bones were too weak to support the child’s weight when he or she started walking. In fact vitamin D was discovered when scientists were hunting for the cause of rickets.

Vitamin D is necessary for the health and mineralisation of bones. However scientists were puzzled by the fact that the vitamin D receptor is present in many tissues, including the brain. If the vitamin only acted on bone cells, you would only expect to find the receptor in osteoblasts. A number of studies were initiated to test the role of the vitamin in other tissues, and they have recently demonstrated a variety of roles for it. A milder deficiency of the vitamin (hypovitaminosis) may not be sufficient to show up as obvious bone weakness, but it can cause a number of psychological and cognitive problems. Of course since these symptoms can have a number of different causes, and since they are less obvious than weak bones, it took a while to work out how important vitamin D was for brain function. Vitamin D insufficiency has now been linked to a number of diseases including type II diabetes, infectious disease, autoimmune disease, neurological disease and even heart disease and cancer.

Vitamin D3, the type synthesised in skin is not the actual active molecule. It is transported in blood to the liver where it is converted to calcidiol. Calcidiol is then released into the bloodstream and ends up in the kidneys where it is converted to the active form, calcitriol. Although there are other forms of the vitamin that can be converted to calcidiol by the liver, vitamin D3 (Cholecalciferol) is the most easily absorbed form, and therefore has the higest bioavailability. Calcitriol can also be synthesised in the white blood cells that form the body’s innate immune defence system, monocytes and macrophages. It acts on these cells to promote phagocytosis and chemotaxis and therefore it increase the innate immune response.

The biologically active molecule, calcitriol, carries out its functions by binding to the vitamin D receptor (VDR), located in the nuclei of cells. The VDR protein belongs to the family of steroid hormone nuclear receptors. This activated the protein and allows it to bind to DNA and activate the transcription of target genes. Examples of genes whose expression depends on vitamin D are transport proteins TRPV6 and calbindin, which are necessary for calcium absorption in the intestine.

Vitamin D is Necessary for the Synthesis of Serotonin

A deficiency of vitamin D has been implicated in many neurological andbehavioural diseases, including autism and mood disorders such as depression. Of course it is always difficult to discover a causal relationship between a lack of vitamin D and a disease. Some people argued that a lack of sunlight could cause depression and the vitamin D deficiency was merely co-incidental.  A paper by a team from Children’s Hospital Oakland Research Institute published in the journal FASEB showed that one of the genes whose transcription is activated by the vitamin D receptor is tryptophan hydroxylase 2 (TPH2). The function of TPH2 is to catalyse the reaction that converts the amino acid tryptophan into serotonin, the neurotransmitter that controls behaviour.  The researchers stated that their data explained the link between vitamin D deficiency and low levels of serotonin in the brain of people with autism. It also explained why autistic children had serotonin levels that were too high in the digestive system. Serotonin synthesis in tissues other than the brain is carried out by the enzyme tryptophan hydroxylase 1 (TPH1) rather than TPH2. And the activated vitamin D receptor acts as a transcriptional repressor of TPH1. The elevated serotonin levels in the gut of autistic patients caused inflammation. |The expression of genes for proteins necessary for the synthesis of two other peptide hormones involved in behaviour, oxytocin and vasopressin are also controlled by the vitamin D receptor.

The research results explained a previously mysterious anomaly of serotonin levels in people with autism, the very low level in the brain and the elevated levels in the digestive system. It also demonstrated that the low brain serotonin levels are connected to the vitamin D deficiency rather then just being coincidental. The research suggests vitamin D supplements as a method of preventing and possibly even treating autism.

However the results are relevant for a host of other neurological and behavioural diseases, not just autism. It is well known that serotonin levels play a crucial part in the development of clinical depression. Most modern antidepressants belong to the class of serotonin inhibitors. If vitamin D is necessary for the synthesis of serotonin, clearly there is a causal relationship between vitamin D insufficiency and depression.

Not only does vitamin D appear to support a stable mood, but it also seems to enhance cognitive function as shown by several studies. In one study in Norway, men were divided into a high vitamin and a low vitamin group, and tested for both executive and nonexecutive cognitive function. The group with high vitamin D levels had significantly more correct responses on the executive functions test than the group that was low in vitamin D.

A different trial looked at the relationship between serum yvitamin D and performance of over 3000 men aged 40-79 years on cognitive tests. The study found a significant correlation between low vitamin D levels and low scores on the Digit Symbol Substitution Test (DSST). This authors suggested studying the role vitamin D might have in preserving brain function in older people.

Vitamin D and Immune Function

Vitamin D also appears to play an important part in modulating immune function. In fact, the kidneys are not the only place where calcitriol, the active metabolite of vitamin D, is synthesised. It is also produced by white blood cells.

The body’s immune system can be divided into two parts, innate immunity and acquired immunity. The innate system consists of cells, like macrophages, that converge on any pathogen and kill it, for example by phagocytosis. No prior contact with the pathogen is necessary to elicit an immune response. Acquired immunity, on the other hand, consists of cells such as lymphocytes that produce antibodies against a pathogen that had infected the organism before. Antibodies are responsible for effectiveness of inoculations and play a crucial role in protecting us from infections. However, there can be a problem when the antibody producing cells are overactive and don’t discriminate between foreign pathogens and the body’s own tissues. Although systems exist that ensure that lymphocytes can recognise ‘self’ antigens and not produce antibodies against them, these systems sometimes fail. The result is autoimmune disease, which can take the form of many different and very serious illnesses, depending on which tissues are attacked by the body’s own immune system. Type II diabetes, lupus, and multiple sclerosis are all examples of auto-immune diseases.

It appears that vitamin D modulates both the innate and the acquired immune response. However, it seems to have the opposite effects on the two types of immunity. It acts to boost the innate response, acting as a cytokine, stimulating chemotaxis and phagocytosis in monocytes and macrophages. Hence vitamin D is important for a healthy immune system and for ensuring we have the ability to fight infections. On the other hand, the vitamin’s effect on B and T lymphocytes, which produce antibodies and control the acquired immune response, is to dampen down their reactivity to antigens, and increase tolerance. This modulates the antibody response and controls antibody production against ‘self’. The overall effect is to help prevent an autoimmune response. Epidemiological research has shown that low levels of vitamin D are one of the risk factors of developing multiple sclerosis, which supports the theory that it helps prevent the immune cells from attacking other cells in the body.

Vitamin D is fat soluble, to ensure its maximum absorption from the digestive tract it has been combined with oil in Natural Stacks’ softgels. Because this is a top quality product, it wasn’t packaged with just any oil which merely serves as a carrier. Natural Stacks’ used premium quality organic coconut oil, possibly the healthiest kind of fat there is. Coconut oil is particularly rich in medium chain fatty acids. These have shorter carbon chains than the fatty acids in normal triglycerides, and are metabolised as soon as they are absorbed, since they have no problems crossing the mitochondrial membranes. They are metabolised to produce ketone bodies. Ketone bodies, unlike fatty acids can cross the blood-brain barrier and be used by the brain for energy. It is thought that medium chain fatty acids can protect the brain against neuro-degeneration, and may improve cognitive function. The other benefits of organic coconut oil may include improved endurance during exercise, appetite suppression, and increased fat oxidation.

Vitamin D3 with Coconut Oil from Natural Stacks is a premium combination of  Cholecalciferol, the form of vitamin D with the highest bioavailability, and organic coconut oil. Vitamin D is mainly obtained from synthesis in a photoreaction that requires UVB rays from sunlight. It is now thought that large sections of the population do not get enough sunlight, and that vitamin D is probably the most commonly deficient vitamin. Vitamin D is necessary for the absorption of calcium and phosphate from the intestine and for the mineralisation of bones. It is also necessary for the synthesis of serotonin, the neurotransmitter that regulates behaviour. A lack of vitamin D is implicated in autism and depression. It has also been shown to affect cognitive function, and to protect against auto-immune disease.

Furhter Reading:

Biological roles of vitamin D:

Health consequences of vitamin D deficiency:

Vitamin D receptor controls the transcription of TPH genes and the level of serotonin:

Vitamin D and cognitive function:

Vitamin D deficiency as a risk factor for multiple sclerosis: