Vitamins – Part 1: A, D, E, K

WARNING: This post is very nutritionally dense (heh), and I’m just going to stop right there…

What do you need to know about vitamins?

  • How much you need
  • What it’s important for in your body
  • What foods are rich in each vitamin
  • What happens when you don’t get enough (let’s try and avoid this).

As there are 13 vitamins with some requiring more detail than others, these posts were split up into a series of two (maybe three posts, there are a LOT of B vitamins!).

What is a Vitamin?

Vitamins are different from three major macronutrients (macro = big) (that’s carbs, proteins & fats). Vitamins are micronutrients (micro = small) found naturally in small amounts in foods, minerals are also micronutrients. They’re important for our body as we cannot make them ourselves and therefore need to consume a sufficient amount to avoid deficiency and the associated health issues that comes with a lack of one or more vitamin.

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Two Main Classes of Vitamins

(1) Water-soluble vitamins: all of the B vitamins and Vitamin C

As the name suggests, these micronutrients can dissolve in water which means consuming too much of these two aren’t really a problem, it’ll be excreted in your urine. However, it often means these vitamins are lost in cooking and processing.

(2) Fat-soluble vitamins: Vitamins A, D, E & K

You can over-do it with these ones, they won’t just get flushed out with a big ol’ glass of water, this usually isn’t a problem but something to be aware of, regardless.

Today I’m focusing on the fat-soluble vitamins, each vitamin will have a mini profile that could be useful for your reference when considering the micronutrient content of your diet/meals/particular foods.

Just a note, vitamins are really important, but as I’ve said before food and meals are much greater than the sum of its nutrients, it’s great to be aware of the nutrient content of your meals but don’t obsess over it. Don’t forgot to enjoy what you’re eating!

Vitamin A

Importance? Growth & development, reproduction/fertility, immune function and vision.

Where from? Butter & animal fat, liver, carrots, eggs, milk & peaches.

How much? A carrot a day (or about half of one) is enough.

What happens if I don’t get enough? Increased rate of infection, poor night vision.

What happens if I have too much? Over a short period of time, you could experience nausea, blurred vision and headaches.

carrots-bunch
Carrots contain the vitamin A pre-curosor beta-carotene.

 

Vitamin D

Importance? Bone health, immune system, regulates calcium metabolism and prevents some cancers.

Where from? The sun, of course! However, some foods have a small amount: UV-radiated mushrooms, fish and margarine. Best to get it from the sun though.

How much? For Sydney in summer 6-8 minutes in the sun most days with just your arms exposed in mid-morning or at mid-afternoon for fair skin, 20-50 minutes for darker skin. In winter, 25 minutes most days at midday for fair skin and 45 min-1.5 hours for darker skin.

What happens if I don’t get enough? Contributes to osteoporosis particularly in elderly women (and some men), weakening bones.

What happens if I have too much? Although vitamin D, itself, doesn’t cause skin cancer, being in the sun too much can have this side effect in extreme cases. Most of us are familiar with sunburn and increased appearance of wrinkles with excessive sun exposure.

Vitamin E

Importance? Protects against cell damage, anti-cancer properties, blood production, maintaining the integrity of each of our cell’s membranes and it’s anti-inflammatory.

Where from? Sweet potato, avocado, almonds, wheat germ.

How much? You need a handful of almonds and half an avo a day, a bit of spinach will also help our daily dose along.

What happens if I don’t get enough? Loss of nerve sensation & coordination.

What happens if I have too much? Pretty hard to do, but it can cause issues with haemorrhaging and affect vitamin A & K levels.

Vitamin K

Importance? Blood clotting and bone health.

Where from? Plant material, vegetable oils, fermented foods (think tofu), cow/calf liver.

How much? A serve of spinach/any dark leafy green will do the trick for a daily dose.

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What happens if I don’t get enough? This is pretty rare as the bacteria in our guts can synthesise vitamin K from the pre-cursors we consume which are found in many foods. It’s usually problematic for newborns if their mother’s breast milk is particularly low in vitamin K. Newborns are given a vitamin K shot after birth as they don’t have the proper bacteria in their gut to produce it themselves and it ensures proper blood clotting occurs should any bleeding occur early in life.

What happens if I have too much? Unless you are being supplemented with a certain type of vitamin K, this is pretty rare.

And there it is, fact sheet number one on the fat-soluble vitamins A, D, E & K.

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