Vitamin D in different life stages: from infants to elderly

Vitamin D is an essential nutrient to help support your immune health, balanced mood, heart health, and strong teeth and bones. You are about to explore its many roles in our bodies and how important Vitamin D is through all different stages of life.

• Vitamin D supplements
• Vitamin D3 and K2
• Vitamin D for the whole family
• Pregnancy and breastfeeding
• Vitamin D for toddler and kids
• Vitamin D for adults and elderly
• Are you getting enough Vitamin D?
• How to make vitamin D go further
• Vitamin D supplements risks and cautions

Vitamin D is often referred to as "the sunshine vitamin" because the main way for our bodies to make it is through exposure to the sun.

When we get sunlight, our skin cells create vitamin D (specifically vitamin D3, otherwise known as cholecalciferol). Our clever liver and kidneys turn Vitamin D3 into its bioactive form – calcitriol – which supports a healthy immune response, balanced mood and calcium and phosphorus levels, which are essential for muscle and bone health.

There are two main forms of vitamin D:

• D3 (cholecalciferol) synthesised naturally by our skin when exposed to sunlight.
• D2 (ergocalciferol) found in plants grown in sunny conditions, like mushrooms.

The main ways Vitamin D supports our health include:

• Immune health
• Calcium absorption
• Strong bones and healthy teeth
• Hormone and mood balance

The best and easiest way to achieve daily vitamin D intake is to expose your skin to sunlight. In terms of foods, in New Zealand it’s common for dairy products to be fortified with vitamin D.

If you’re after natural food sources of vitamin D, the best options are:

• Liver
• Egg yolk
• Oily fish like mackerel, tuna and sardines

Cod liver oil could be the best food source of vitamin D. It’s popularity in Scandinavian cuisine and culture is for good reason. In these regions, daylight can be sparse for many months of the year.

Many factors influence sunlight absorption:

• Season – in winter months, there are less opportunities for sun exposure.
• Location – geographic factors influence the strength of UV rays and how long you can safely stay in the sun.
• Skin tone – darker skin tones need more time in the sun to make vitamin D.
• Time – when the sun is high in the sky (between 11am and 3pm), UV rays are stronger and vitamin D production can happen quickly. During these times the sun is harsh, and it is less safe to spend long periods of time outdoors without shelter. If you are outside during this time window, sunscreen, hat and sunglasses are important. A more suitable time to get sun exposure may be first thing in the morning – which is also great for setting your circadian rhythm. Long story short, always balance sun exposure with the appropriate skin protection.

When sun exposure isn’t possible, it’s tricky to get enough vitamin D from food alone. That’s where supplementation can come in handy. Vitamin D supplements come in all kinds of different forms. This includes capsules, tablets and liquid drops. Dosage is typically measured in micrograms (mcg) or international units (IU).

The New Zealand Nutrition Foundation recommends a minimum daily intake of:

• 5mcg (200 IU) for infant, children and adults.
• Increasing up to 15mcg (600 IU) for over adults 70+.

When considering a vitamin D supplement, a daily dose of 1000IU over the cooler months is usually suitable.

Adding a vitamin D supplement can be especially helpful if you’re:

• Living in cold areas with limited sun exposure
• Moving towards an autumn or winter season
• Over the age of 55 and want to focus on supporting bone health

Vitamin D in supplements is often paired with Vitamin K2 for its synergistic effect:

• Vitamin D3 supports calcium absorption
• Vitamin K2 supports calcium utilisation by guiding it to bones and teeth.

What is Vitamin K2 good for? This vitamin has the important function of directing calcium to the bones. It’s present in fermented foods and produced by the good bacteria living in our gut.

Note: Vitamin K in contraindicated for individuals taking anticoagulant medications or other blood thinners. Make sure you chat to your healthcare provider to make sure vitamin K is right for you.

As babies, having enough vitamin D is important for growing strong, healthy bones and teeth. As we go through life, it supports a healthy immune response, balanced hormones and mood, muscle health and bone density.

• Suitable for all family members over 3
• Small tablet with delicious mango flavour
• Healthy daily dose of vitamin D3 and vitamin K2

Vitamin D is especially important during pregnancy and breastfeeding to support the extra health requirements of mums and growing bubs. For immune health and proper calcium absorption, bone growth and healthy development support, vitamin D supplementation is often worth considering.

A comprehensive  pregnancy and breastfeeding multivitamin will often cover most nutritional bases, but it’s always a good idea to chat with your midwife or health care professional to make sure your changing body is supported in all the ways it needs.

• Quality prenatal multis (like this) provide high-dose vitamin D
• Supports baby’s growth and mum’s nutrients
• Key pregnancy & breastfeeding nutrients - 2 caps with breakfast

Breast milk provides essential nutrients, but it may not contain sufficient vitamin D to meet the needs of the growing baby. For exclusively breastfed babies, often vitamin D3 supplementation is recommended. Healthcare consultation helps determine appropriate dosages, supporting maternal and infant health at best.

Getting well rounded nutrition, including proper vitamin intake, is especially important for children - supporting growth, development, and overall health. Diet, sun exposure, and supplementation can all play a role in getting their daily vitamin D. 

Risk of vitamin D deficiency in children can have many effects on health, particularly when it comes to bone development. Low vitamin D levels can lead to a condition called rickets, which can give you weak, soft bones.

Left untreated, rickets can lead to bone deformities, stunted growth, and higher risk of fractures. Always chat to your health care provider first if you feel like your child needs extra nutritional support.

This essential nutrient plays a significant role in every stage of our lives and becomes particularly important as we age. Age-related changes, reduced sun exposure, and a changing metabolism can contribute to lower vitamin D levels in the body.

Low vitamin D levels are linked to bone loss, increased risk of falls, and decreased bone density. Brittle bones are prevalent in older adults, especially post-menopausal women.

Here are some tips to help you figure out if you’re getting your daily dose of vitamin D:

• Sun exposure: are you spending 20 minutes a day outside, exposing your skin to the sun? Try to aim for about 10-30 minutes of safe sun exposure each day.
• Consume vitamin D-rich foods: do you eat fatty fish or liver regularly? Aim to include these foods in your daily diet, or fortified products like milk, yogurt and some cereals.
• Take a vitamin D supplement: do you live in a cold region, with limited sunlight? A vitamin D supplement might be right for you. 

The best way to check vitamin D levels is through a blood test. Chat to your health care provider to figure out if this is the best choice for you.

Combining vitamin D with other immune-supporting ingredients can provide an extra layer of support. Some companion products include key nutrients like:

• Vitamin C – a powerful antioxidant, for immune support
• Zinc – for healthy immune and tissue support

Here’s some other key players to look out for:

• Calcium - essential for supporting bone structure and strength
• Magnesium – for supporting calcium absorption and bone mineralisation
• Boron – supports the metabolism of calcium and magnesium, crucial for bone health.

• Vitamin D, magnesium, and calcium
• Comprehensive support for bone health
• Includes 72 trace minerals, including boron

Since Vitamin D is fat-soluble, any excess gets stored in the liver. Vitamin D overdose can occur with long-term, high-dose supplementation.

In New Zealand, high dosing over 1000IU is only available with a doctor’s prescription. While being essential for health, excessive intake can lead to toxicity and cause unwanted effects.

Supplementation is usually safe, but it's important to be aware of all outcomes associated with its use. Consulting with a healthcare professional before starting any supplementation is the best way to take charge of your health.