Can you OD on D?

We know that vitamins and minerals are essential. But do supplements work and how much is too much?

My doctor told me I am deficient in Vitamin D. I’ve been told this before and have taken supplements to address the issue. Curious…

Vitamin D, Google tells me, assists in the building and maintenance of healthy bones. We thought that was the job of calcium didn’t we? We were right, because your body can only absorb calcium, the primary component of bone, when vitamin D is present.

It’s anti-inflammatory, antioxidant and neuroprotective properties support immune health, muscle function and brain cell activity. For all of this to be activated the recommended daily intake is 400 international units (IU).

So, how do I get 400 IU into my body and doing its best to keep me healthy?

Vitamin D isn’t naturally found in many foods, but you can get it from fortified milk, fortified cereal, and fatty fish such as salmon, mackerel and sardines. Your body also makes vitamin D when direct sunlight converts a chemical in your skin into an active form of the vitamin (calciferol).

The amount of vitamin D your skin produces from exposure to the sun depends on many factors, including the time of day, season, latitude and your skin pigmentation. Depending on where you live and your lifestyle, vitamin D production might decrease or be completely absent during the winter months. Sunscreen, while important to prevent skin cancer, also can decrease vitamin D production.

In Singapore you’d think we’re in great shape but if you think about it, most of us take great pains to avoid the sun for various reasons and therefore may miss out on what we need.

Many older adults don’t get regular exposure to sunlight and have trouble absorbing vitamin D. If your doctor suspects you’re not getting enough vitamin D, a simple blood test can check the levels of this vitamin in your blood – that’s how I found out.

If you think you’re getting enough vitamin D, there may be something going on that inhibits absorption, like Crohn’s disease, kidney disease, certain medication or a BMI higher than 30 (there’s my problem). 

The point here is that being aware of what vitamins do for your body, how you can make up for any detected shortfall and how to improve absorption are all things that Google (and preferably your doctor) can help you with.

Those international units are for each vitamin are widely available online so you can quite easily monitor your requisite consumption, after you’ve had a doctor advise you of where your shortfalls might be.

Can you have too much?

Taking vitamins is part of the daily routine of millions of people worldwide. Although directions for safe consumption are listed on most supplement bottles, it’s common for people to take more than what’s recommended and taking too much of some nutrients can be dangerous.

The 13 known vitamins are divided into 2 categories — fat-soluble and water-soluble. Water-soluble vitamins include vitamin C and eight B vitamins. Because water-soluble vitamins aren’t stored but rather excreted through urine, they’re less likely to cause issues even when taken in high doses.

Unlike water-soluble vitamins, fat-soluble vitamins do not dissolve in water and are easily stored in your body’s tissues. They are:
  • Vitamin A
  • Vitamin D
  • Vitamin E
  • Vitamin K

Given that fat-soluble vitamins can accumulate in the body, these nutrients are more likely to lead to toxicity than water-soluble vitamins.

While rare, taking too much vitamin A, D, or E can lead to potentially harmful side effects, although taking high doses of non-synthetic vitamin K seems to be relatively harmless, which is why an upper intake level (UL) has not been set for this nutrient.

Upper intake levels are set to indicate the maximum dose of a nutrient that’s unlikely to cause harm for nearly all people. So, take note of these and don’t treat them like M&Ms.

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