Vitamin D, the Sunshine Vitamin: Who Needs Supplementation?

Posted on Friday, August 17th, 2018
Vitamin D is a fat-soluble vitamin, which is also known as the sunshine vitamin. It exists in three main compounds, which are vitamin D1, D2, and D3. Human skin does synthesize this vital vitamin after getting exposure to sunlight (UV rays) although; if one gets deprived of enough sunlight, there are vitamin D supplements to use. Vitamin D deficiency has a severe effect on human health, and about 1 billion people worldwide are estimated to suffer from it. Between ’90 and 2000s, the rate of vitamin D sufficiency dropped from 60% to as low as 30% according to Fresh Thyme Farmers Market. Lack of enough Vitamin D in blood serum is associated with several disease and bone issues like explained below.

Biological synthesis of Vitamin D

The two main Vitamins that your body needs are vitamin D2 and D3 although produced and ingested differently. For Vitamin D2, it’s primarily found in mushrooms generated through ultraviolet irradiation. But many people do not feed on mushrooms. Vitamin D3 is the most natural and synthesized on human skin. When human skin gets exposed to UVB light, D3 is synthesized. Additionally, some oily fishes like mackerel, salmon, and herring are sources of this vital vitamin too. This vitamin first gets incorporated by chylomicrons and then absorbed into the blood venous through lymphatic system ready for hydroxylation in the liver. Vitamin D-25-OHase (hydroxylase) converts vitamin D from sunlight into 25(OH)D vitamin compound. From there, the 25(OH) D is taken into the kidney for final hydroxylation into D1, 25(OH) D ready to take effect on your body.

Consequences of Vitamin D Deficiency (VDD)

In case vitamins (25(OH) D) is not enough, abnormalities in the absorption of phosphorus and calcium results. VDD reduces intake of phosphorus and calcium by 60% and 10-15% respectively. Remember, your bones development depends on these two minerals. Deficiency or abnormalities of the two minerals causes less secretion of Parathyroid hormones (PTH), which is key in remodeling, development, and strengthening of bones. Reduced bones mineral density (BMD) caused by low PTH causes osteoporosis or osteopenia. These two conditions are blamed for increase fall and fractures susceptibility. In children, this deficiency causes rickets, weak muscles, walking/standing difficulties and low immunity for all ages. Below are vitamin D micrograms (1 microgram = 40 IUs) needed at different ages:
  • Infants (0-12 months) – 10 mcg (400IUs)
  • Children (1 -18 years) – 15 mcg (600IUs)
  • Adults up to and below 70 years – 15 mcg (600 IUs)
  • Adults above 70 years – 20 mcg (800 IUs)
  • Lactating/ expectant Mother -15 mcg (600 IUs)

Who needs Vitamin D Supplementations?

There are times when exposure to sunlight becomes limited due to life activities or when body conditions become inhibiting to Vitamin D conversion. Such are the times when you need scientifically proven dietary supplements. Below are groups of people who need Vitamin D supplements.

Old adults

Several factors attached to old age escalate the risk of VDD. At a senior age, a lot of skin degeneration does happen. Mostly, wrinkles formation wreaks havoc on the epidermal skin mass that reduces skin surface exposed to sunlight. Secondly, at that old age, many senior persons spend most of their time indoors. Many do so due to reduced outside activities and others due to old age-associated illness. Such are the factors that minimize exposure to sunlight, which triggers the natural synthesis of vitamin D by the skin. Thus senior persons need to incorporate vitamin D supplements in their diet.                                                                                                   

Breastfed infants

Infants depend on mother’s breastfed milk for food and energy. At this time, most mineral, vitamin, and nutrients are mostly dependent on what is contained in their mother’s body. For some reasons, it becomes somehow difficult for a mother to provide enough Vitamin D according to the infant need. Breastfed milk mostly provides between 25-75 international units (UI) per liter. Not many mothers who meet the amount needed and thus supplementation of about 400 UI/L should be done every day.

People with Limited Exposure to Sunlight

This condition mostly touches on women, career persons and religious doctrine people who cover most parts of their bodies. People of such line of life can suffer from vitamin D deficiency because most of their body parts are ever covered. This skin coverage by cloths or robes does cut skin exposure, and little or no UV light reaches their skin. On the other hand, there are those who use sunscreens. Sunscreens are associated with 95% blockage of UV light. These kinds of people are thus bound to depend on Vitamin D supplements or food types that are significant sources of vitamin D though few.

Dark skinned people

This is not meant to be a contradicting statement, but excess melanin pigmentation reduces UV light absorption used in vitamin D synthesis, and on the other hand, little melanin pigmentation can result to skin cancer due to excess UV rays. But on this topic; excess melanin pigmentation on the top skin layer (epidermis) reduces vitamin D synthesis. Inhibition of ultraviolet rays reduces formation 25 (OH) D that is the needed Vitamin D final compound. 

Those with Malabsorption of Fat

Vitamin D is a soluble fat. For this reason, it requires some additional fat compounds to be absorbed and get transported throughout the body. For those who have Crohn’s diseases, liver diseases or cystic fibrosis, they do experience fat malabsorption. Due to such malabsorption issues, they need to incorporate fat foods like avocados when taking Vitamin D containing food to aid in its absorption. Additionally, they need to intake Vitamin D supplements to maintain the required amount in the body.

Obese people

Those people who have a body mass index or 30 and above, need additional vitamin D sources (supplements). Overweight people have large subcutaneous fat amounts. The elevated vitamin captivation within their excess subcutaneous fat takes more vitamins thus reducing the vitamins level which circulates in their blood to help in synthesis of 25(0H) D. Thus, and obese stricken people need to intake more vitamin intake through supplements to achieve the required Vitamin D level. There are few vitamin D supplements food types. They include oil fish, red meat, eggs, breakfast cereals, Olive oil, fortified milk, and fortified orange juice. It is thus advisable to turn to these supplements and bar off Vitamin D deficiency effects. For reasonable diagnostics, the measure of serum 25 hydroxy-vitamin is advised. This helps one follow the D2 and D3 vitamin treatment supplement out of an informed point. But by following the supplement plan or treatment, VDD issue can be completely dealt with.
References: 

www.nal.usda.gov/fnic/DRI/DRI_Calcium/250%E2%80%93287.pdf

https://www.ncbi.nlm.nih.gov/pubmed/17556697

https://www.ncbi.nlm.nih.gov/pubmed/15797954

https://www.ncbi.nlm.nih.gov/pubmed/18977996

https://www.ncbi.nlm.nih.gov/pubmed/2349922

https://www.ncbi.nlm.nih.gov/pubmed/4050723