Vitamins: What, Why and Where

By Catherine Saxelby

Learn all about the 14 vitamins your body needs for healthy living – their functions, benefits and food sources.

Here you will find in-depth, quality information on the vitamins – all in one place. It is a trusted resource for people seeking to make sense of the plethora of often-confusing information about vitamins and supplements.

Learn where vitamins are naturally found, how much your body needs each day, the richest sources, symptoms of overdose and deficiency, the official Recommended Dietary Intakes (RDI), easy ways to get your day’s needs and how cooking or processing affect each vitamin.

Whether you're looking to boost your health during pregnancy, to slow aging or you're just feeling run down, this guide about vitamins and supplements will give you all the information you need.

You will find complete usage and dosage recommendations for the 14 basic vitamins.

You’ll be guided through the options that are likely to do you some good, and warned of those with the potential to harm.

With clear understandable explanations, the most current scientifically documented guidelines, and easy-to-follow lists, Vitamins – What, Why and Where is your concise, to-the-point guide.

• Language: English
• Publisher: Foodwatch Pty Ltd
• Release date: Jul 23, 2018
• ISBN: 9780987552143

Catherine Saxelby

Catherine Saxelby B Sc, Grad Dip Nutr Dietetics, APD, AN is Sydney-based culinary nutritionist and award-winning author of 12 books. She has contributed to many magazines such as Healthy Food Guide, Prevention and New Idea, and has appeared on TV programs including Good Morning Australia and Today. She runs an informational website at www.foodwatch.com.au where she shares her discoveries about nutrition, diets and additives. Connect with Catherine on Facebook, Twitter, Instagram, LinkedIn and Pinterest.

Book preview

Copyright

Introduction – Hello from Catherine

Hello and welcome.

Thanks for buying this book. There seems to be so much hype and conflicting information out there on vitamins. My aim is to look beyond the claims and give you the facts you really need in order to make informed decisions. In this book, you’ll discover what vitamins are, how much you need each day and where to find them – as well as delicious ways to get your daily dose.

In the world of nutrition, vitamins remain a perennially popular topic. Their impact on our health – both positive and negative – generates endless discussion and media stories. Remember these headlines?

Can vitamin C really fight off the common cold?

Mushrooms: B12 for vegans?

Folate added to cereals and bread to prevent birth defects in newborn babies.

Vitamin D – the sunshine vitamin – found to be low in many older folk.

As a nutritionist, I am asked about vitamins all the time: How can I tell if I’m deficient in any vitamin? Should I take a supplement as ‘insurance’? What about popping some vitamin C if I feel a cold coming on? I’m vegetarian – do I need extra vitamin B12? Are there downsides to taking extra vitamin E for months and months? And so on.

As vitamin supplements – tablets or capsules, tonics and powders – become increasingly popular, it’s even more important to know the facts. It’s true that some supplements have a positive role in keeping us healthy, like the folate taken pre-conception and during pregnancy or the fish oil that helps the body in myriad ways, from thinning the blood to aiding vision. But many supplements are unnecessary and only serve to fuel the bank balances of pharmacies, health food stores and unscrupulous online hustlers.

I find the whole subject of vitamins fascinating. With new research appearing weekly, it’s an area of nutrition I believe is full of hope and inspiration. It’s such a feel-good topic and one that is a real positive in nutrition – such a contrast to all the controversies surrounding carbs and fats and weight loss … you know what I mean!

How to get the most from this book

This is a book to dip in and out of. You don’t need to read it from cover to cover, although I won’t mind if you do. Use it to:

Look up how much of a particular vitamin you need

Discover the richest food sources of each vitamin

Check out the impact of overdose

Find out the deficiency signs to look for

Convert between micrograms, milligrams and IUs

Read up on interesting issues.

Why me?

I feel I’m the best to write about this whole topic. I’ve been a nutritionist for almost 30 years and keep a watchful eye on the research. I’ve observed many cycles of interest – just think about the hype about vitamin C to prevent colds, carotenoids to help sooth bad sunburn, thiamin being added to bread and possibly beer (never accepted), getting enough vitamin D without sunlight and whether mushrooms actually produce any vitamin B12.

I first started writing about vitamins, both as an overall topic and from a single vitamin focus, way back in the 1990s. For instance, when folate first became a vitamin of note, I worked with a breakfast cereal company who had started adding folic acid to their products and wanted to publicise the fact.

Plus I started writing about more general things like the whole notion of taking tablets compared to the more old-fashioned view of food tonics. And how a hangover drink loaded with B vitamins works compared to a single tablet of B1. That sort of thing.

On a personal note, I’ve brought up two kids and been through the usual paediatric panic about iron for little ones who refuse to eat meat (or much of anything), DHA supplements for brain development, and the whole problem of getting children to take any sort of pills.

Plus I’m big on eating a nutrient-dense diet so you get plenty of vitamins from natural sources such as vegetables, fruits, nuts, seeds, lean meats, eggs, fish and whole grains.

Remember

As a guide, the Recommended Dietary Intakes (RDIs) I've quoted in this book come from the Nutrient Reference Values (NRVs) as spelled out by the National Health & Medical Research Council (NHMRC) for Australia and the Ministry of Health (MOH) for New Zealand in 2006. The 2006 figures are the latest available, and are not very different to those in the UK and USA so you can easily cross-check across countries.

Without more ado, let’s start!

Regards

Catherine

Units and measures

Units for measuring vitamin intakes

In this book, you'll see figures for the recommended day's intake of the individual vitamins:

These figures are for all of the life stages for adults as well as for infants and children. Children generally need less than adults due to their lower body weight.

Recommended intakes are taken from the Nutrient Reference Values (NRV) for Australia and New Zealand, NHMRC 2006. Recommended amounts are given in milligrams (milligrams) or micrograms (µg), depending on the nutrient.

The Recommended Dietary Intake (RDI) is the amount that is estimated to cover the needs of practically all healthy people in a population, although individuals vary in their true requirements.

The Adequate Intake (AI) figure is used when an RDI cannot be determined.

Upper Limit figures are sourced from the NRVs as listed above. The Upper Limit is the highest quantity you can take from either food or supplements without having to worry about any side-effects.

The food values used to create the easy ways to get your daily intakes were sourced from AUSNUT 2011–13. They are based on the suggested intake for an adult woman.

Chapter 1

What are vitamins?

Vitamins are a group of organic compounds needed by our bodies in minute quantities. They are essential for good health and for growth in children. While they do many jobs, they mostly work as enzymes or catalysts to facilitate and ‘speed up’ biochemical reactions in the body. Think of them