By Dr Arun Mahtani
It’s the summer season, the Sun is out and the heat is on! Every single day seems to be a drag as the sun continues to shine with no mercy and makes us fatigued and dehydrated.
But all is not lost, even in this sweltering heat one can make use of this key component to improve our bone health and immunity and that is Vitamin D. You heard it right! The sun is the primary source of vitamin D. So how does our body utilize this source? Well we are about to find out!
The Making of Vitamin D:
So not only do you need sunlight, you also need a healthy liver and kidney to have adequate vitamin D.
Vitamin D is also found in certain foods and dietary supplements in which case absorption occurs from the intestines in the pre vitamin form.
Since we have an idea of how it’s made let us now discuss its role in the body!
Vitamin D-Yay or Nay?
Of course Yay! But overdosing through supplements can have some harmful effects on the body which we shall discuss later.
It is common knowledge that vitamin D is needed for bone health. But in recent years there have been numerous studies which have shown many other benefits of Vitamin D. Let us see how that happens.
Vitamin D helps to maintain an adequate balance of calcium and phosphorus in the blood. It helps maintain the normal mineralisation of the bones. It is also needed for bone growth, bone remodeling and mineralization of collagen.
Also Vitamin D helps in improving our overall immunity. It reduces production of inflammatory cytokines and increases the levels of anti-inflammatory cytokines in our body. Cytokines are substances that are secreted by our immune cells and are linked with the pathophysiology of various diseases.
Deficiency of vitamin D has been linked with causation of many autoimmune diseases like Rheumatoid Arthritis (RA)- affects joints, Systemic Lupus Erythematosus (SLE) - a multi system disorder, Multiple Sclerosis (MS) -an autoimmune disorder affecting the nerves in our body and inflammatory bowel disease (IBD)- affecting the intestines.
Vitamin D has also been linked with a reduction in incidence of certain types of cancers. These include colorectal, breast , pancreatic and prostate cancers. It does so by reducing the growth of cancer cells, promoting cancer cell death and reducing tumor blood vessel formation.
Foods Rich in Vitamin D and Daily Requirements
The daily maintenance dose of vitamin D varies by age, but most children and adults generally require 600-2000 IU of vitamin D daily. For vitamin D-deficient children and adults, higher doses of vitamin D given weekly are recommended.
Food items rich in Vitamin D are :
Dairy products like milk, cheese, curd, ghee, paneer
Fruits like mango, papaya, melons, apple, peaches, apricots, avocado, oranges
Vegetables like sweet potato, carrots, leafy vegetables, capsicum
Nuts like almonds, pista
Fortified breads, cereal
Liver, red meat
Deficiency in Adults:
Joints and Bone pains
Difficulty in walking
Osteoporosis - porous and brittle bones
Pathological Fractures – even trivial injuries causing major fractures
Deficiency in children
It causes a condition known as rickets.
Delayed closure of openings of the skull known as fontanelles (most important one is the soft opening you can feel on top of babies heads)
Bulging of the skull bones
Beaded appearance of the chest (bony necklace appearance) and formation of a groove near the lower end of the chest
Bowing of the legs and forearms
Widening of the wrists and ankles giving a lumpy appearance.
Delayed growth of teeth
Who is at risk for developing Vitamin D deficiency?
Age > 70 years
Those who have diseases of the intestines like Crohn's Disease, Celiac Disease, Chronic Hepatitis, Chronic Pancreatitis, major gastric or intestinal Surgeries because of which vit D is not absorbed properly
Poor dietary habits.
Dark skinned individuals who require longer time in the sun to produce vitamin D
People using excessive sunscreen/ thick moisturisers that interfere with absorption of UV rays by skin/ wearing fully covered clothes that does not allow exposure to sun.
Infants being exclusively breast fed and not exposed to sunlight.
Obese individuals, individuals who spend most of their time indoors or in artificial lighting.
Hospitalized or institutionalized individuals.
Medication interfering with the metabolism of Vitamin D such as Steroids and Anti-seizure medications.
Population residing in places above 37 degrees latitude where sunlight is less.
Be careful with those supplements!
Even though Vitamin D has its many benefits, excess intake of Vitamin D via supplementation can lead to an increased level of calcium in the body. This excess calcium is excreted in the urine and predisposes to the formation of calcium stones in the kidney. It can also cause gastrointestinal symptoms like nausea, reduced appetite and constipation. Also cognitive disturbances like depression and anxiety have been reported with excess calcium levels.
So think twice before pop that vitamin pill and consult your doctor for advice.
I hope this article gave you some useful information regarding Vitamin D - Its function in the body, its benefits, deficiency symptoms and adverse effects if supplementation is taken in excess.
Once you're done reading this article make sure you head out and soak up the sun to
get your daily dose of D!
Dr Arun completed his MBBS from JSS Medical college, Mysore. He is certified in Advanced Diabetes management, Cleveland clinic and is currently pursuing his USMLE exam certification. His interests are medicine and pediatrics with special focus on cardiology. He is actively involved in multiple research projects and has also contributed health articles in the online portal Heartsense