The Importance Of Vitamin D: Is It A Supervitamin Or Are We Prey To A Superhype?

The importance of Vitamin D for women (and in fact for all) cannot be dismissed – however, we need to learn more about its role and how much Vitamin D we actually need.

In all probability, you would have had your Vitamin D levels tested sometime or the other. And the numbers on the blood report would have been the center of many discussions.

With claims of Vitamin D being protective against everything from cancer to covid, this vitamin always seems to be in the news. Let us put the spotlight on this vitamin, which has also been called the sunshine vitamin.

Bone health in our body depends on a balance between two processes – Bone formation (or ossification) and bone resorption (or remodeling). Bone resorption is a process in which calcium from bones is broken down and released into the blood. In bone formation, calcium is deposited in the bones. When the speed of bone formation and resorption are equal, the bone mineral density (BMD) is normal, and our bones are healthy, strong, and resilient.

When bone formation does not keep up to bone resorption, bones become weak, thin, brittle, and easily fractured. This is called osteoporosis (Translates to porous bones). Vitamin D is responsible for the absorption of Calcium from the gut. This is how it plays a central role in this balance of resorption and formation.  The deficiency of Vitamin D in children is called rickets, and deficiency of Vitamin D in adults is called Osteomalacia. (Translates to soft bones)

Women and Vitamin D

Bone health is a delicately balanced metabolic activity in both sexes. But women are often more prone to osteoporosis (thinning of bones) because the bones are thinner and less dense. During menopause, estrogen levels decrease. With this, bone formation slows down, increasing the risk of osteoporosis.

Even before menopause, deficiency of Vitamin D has been linked with fertility issues, healthy pregnancies, endometriosis, and polycystic ovary disease, making it an essential nutrient for reproductive health

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The other superpowers of Vitamin D?

Vitamin D is essential for the health of the muscles and reduces inflammation. The growth of cells is also regulated by Vitamin D along with other substances. Thus Vitamin D is essential for general well-being and health. But large studies across the world have not found a definite link between Vitamin D levels, and risk of cancer, diabetes, or covid

Why is there so much confusion about Vitamin D deficiency, and how can you ensure that you have enough Vitamin D in your diet?

Animal foods, especially fatty fish are an important source of Vitamin D.  A few plant sources, like mushrooms, are rich in Vitamin D.  Ensuring adequate Vitamin D intake can be difficult in vegetarians and vegans. This is why a lot of foods are fortified with Vitamin D, esp. dairy products, soy and almond milk, juices, and cereals.  Infant foods formulas are also usually fortified. It is important to be mindful of getting adequate exposure to direct sunlight. The most widely used recommended dietary allowance (RDA) for vitamin D is 600 IU daily for adults up to age 69 and 800 IU daily for people older than 70.

Ultraviolet (UV)-B radiation (present in the sunlight) penetrates the skin and helps in the formation of Vitamin D.

Vitamin D from sunlight, food, and supplements is not in its active, usable form. Conversion of Vitamin D into its active form is a two-step process. Vitamin D is first converted to 25-hydroxy-vitamin D (also called calcidiol) in the liver. This 25-hydroxy-Vitamin D  is finally converted to 1,25 dihydroxy Vitamin D (also called calcitriol) in the kidney.

Who needs a Vitamin D test?

General testing for Vitamin D as a screening test is not recommended. In case of prolonged weakness, bone pain, being prone to fractures, or other symptoms your doctor may suspect Vitamin D deficiency and suggest you get tested. 

Some people on long-term medicines for epilepsy, patients who have had weight loss surgery, or other abdominal surgeries can also be at risk of vitamin D deficiency.

What are we measuring and what do the numbers mean?

25 hydroxyvitamin D stays stable in blood for longer, and this is what is measured in blood tests. It is a good and reliable indicator of the active vitamin D levels in our body.

What does my report mean? Is there a cut-off value that decides Vitamin D deficiency?

The normal range of vitamin D is measured as nanograms per milliliter (ng/ml). Many experts recommend a level between 20 and 40 ng/ml. Others recommend a level between 30 and 50 ng/ml. 

While testing for Vitamin D has become more and more common, it is important to understand that Vitamin D metabolism varies in each person. Darker-skinned people are relatively resistant to the action of UV rays, hence they produce less Vitamin D. Also, how much vitamin D is converted to its active form in the body is different for different people.

Lastly, each of us needs different levels of vitamins to ensure a healthy metabolism. Simply put, the same level of Vitamin D in the blood may be adequate for one person, while another one with the same level may be deficient. This is why, it is not possible to define a single cut off value for Vitamin D.

A broad normal range is used as a guide to the level of Vitamin D in the blood, but the decision of Vitamin D supplementation should only be made when a doctor evaluates both the patient and the test report. Treating or fixing the number on the test report does not work because individual factors need to be considered.

More is better, right? We can add Vitamin D pills to our daily routine?

Actually No. Increasing vitamin D levels, beyond the required levels is not beneficial. As the vitamin is stored in the body, it can even lead to health problems, hence supplements should be taken only when advised by the doctor, and for the duration recommended.

This is also why your doctor may recommend these supplements for few weeks, and not on a regular basis. Another reason to follow your doctor’s advice is that preparations available in the market often contain different forms of Vitamin D. Some forms are better absorbed and more effective. Multivitamin supplements may have vitamin D in low doses too. While these may work for some people, others may need specific supplements to raise their Vitamin D levels.

 So here is what you need to remember:

• Try and add natural and fortified sources of Vitamin D in your diet
• Ensure direct exposure to sunlight as and when you can.
• See your doctor if you have concerns about your Vitamin D levels and discuss the test results with them. Follow their recommendations if they prescribe supplements
• If you are already taking Vitamin D or other supplements, do let your doctor know.

Image credits: Dam Smith/Getty Images via Canva Pro

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