Vitamin D 1000iu

Australia has more sunshine than almost anywhere and still has a real vitamin D problem. These are the questions our naturopaths ask in store to work out who needs a supplement and who needs a blood test first.

A good fit if

• You work indoors, do shift work, or are housebound, so you rarely get midday sun on bare skin
• You have deeply pigmented skin, or you cover most of your skin for cultural, religious, medical or work reasons
• You live in Victoria, Tasmania or the ACT, where winter deficiency rates are highest
• You're over 70, when your skin makes vitamin D less efficiently and the Adequate Intake is three times the adult figure
• A blood test has shown your 25-hydroxyvitamin D is below the adequate level and you want a maintenance dose

Check with us first if

• You take thiazide diuretics (water tablets). Combining them with vitamin D raises the risk of high blood calcium.
• You take digoxin or another cardiac glycoside. Their effects may be stronger when vitamin D is taken with calcium.
• You take anticonvulsants, barbiturates, corticosteroids, orlistat or a statin. Each can change your vitamin D levels or be changed by them.
• You have coeliac disease, Crohn's disease, cystic fibrosis, untreated malabsorption, or have had bariatric surgery. How well you absorb a fat-soluble vitamin is hard to predict.
• You have kidney disease or a history of kidney stones. Dose and monitoring are a medical decision.
• You're pregnant or breastfeeding. Vitamin D is routine in pregnancy care, but your midwife or doctor should set the dose.
• You're buying for a baby or child. Children's drops are dosed differently, and the infant Upper Level is far lower than the adult one.
• You already take a multivitamin, calcium tablet, fish oil or immune formula. Check every label before adding another source.
• You want a D3 with K2 product and take warfarin or another blood thinner affected by vitamin K.

• Vitamin D3 (colecalciferol). Best known for: The default on Australian shelves and the same molecule skin makes in sunlight. Absorption: Raises 25-hydroxyvitamin D further and holds it longer than an equal dose of D2. Typical use: Capsules and tablets, most commonly 1,000 IU (25 µg) once daily with a meal containing fat.
• Vegan D3 from lichen. Best known for: D3 potency without lanolin, which is sheep-wool derived and rules standard D3 out for many. Absorption: Chemically identical to lanolin-derived D3, so it behaves the same in the body. Typical use: Capsules and drops for vegans and anyone avoiding animal-derived ingredients.
• Vitamin D2 (ergocalciferol). Best known for: The fungal-derived form, vegan by default and used in UV-exposed mushrooms. Absorption: Well absorbed but raises and sustains blood levels less effectively than D3. Typical use: Uncommon on Australian retail shelves; more often met through fortified foods.
• D3 with vitamin K2. Best known for: Pairing D with the vitamin involved in directing calcium into bone rather than soft tissue. Absorption: The D3 component behaves as it always does; K2 is a separate nutrient, not an absorption aid. Typical use: Capsules and drops, popular alongside calcium; not suitable on blood-thinning medicines without advice.
• Liquid drops and oral sprays. Best known for: Flexible dosing and an option for people who cannot swallow capsules. Absorption: Comparable to capsules for most people; the oil base matters more than the delivery format. Typical use: One or two drops or sprays daily; the format usually chosen for infants and older adults.
• Combination products. Best known for: Vitamin D bundled into calcium tablets, multivitamins, fish oils and immune formulas. Absorption: No different, but the dose is small and easy to overlook. Typical use: Add up every product you take. This is an easy nutrient to double up on.

Reference values. The NHMRC Nutrient Reference Values set an Adequate Intake rather than an RDI: 5 µg a day from infancy to age 50, including pregnancy and breastfeeding, rising to 10 µg a day for adults 51 to 70 and 15 µg a day from 71. The reference values note that vitamin D from food adds to what your skin makes in the sun, so the figures assume sunlight is doing most of the work.

Typical supplemental range. Australian labels use international units, where 1 µg equals 40 IU. Most products contain 400 IU (10 µg) for babies and children and 1,000 IU (25 µg) for adults, which is the most a listed medicine is allowed to contain. Healthy Bones Australia suggests 600 IU a day for adults who get some sun, 800 IU from age 70, and 1,000 to 2,000 IU for people who avoid the sun and other at-risk groups.

Upper level. The NHMRC Upper Level of Intake is 80 µg a day (3,200 IU) from age one, including pregnancy and breastfeeding, and 25 µg a day for babies under 12 months. Higher short-term doses are sometimes used to correct a diagnosed deficiency. Healthy Bones Australia describes 3,000 to 4,000 IU a day for six to twelve weeks, but that's a clinical decision made after a blood test.

Worth knowing. Too much vitamin D comes from supplements, not sunlight. It's rare, and it means high blood calcium at levels far above what's needed. Australia's common problem is the opposite, and the answer depends on your skin type, where you live and what your blood test says. What you need depends on your age, diet and health, so talk to one of our naturopaths.

Food first, where the diet allows it.

• Cod liver oil: about 34 µg (1,360 IU) per tablespoon: by far the densest source
• Oily fish such as salmon, trout, mackerel and herring: roughly 14–16 µg (570–645 IU) per 85 g serve
• Mushrooms exposed to ultraviolet light: about 9 µg (366 IU) per half cup; ordinary mushrooms grown in the dark supply almost none
• Fortified milk and plant milks: roughly 2.5–3.6 µg (100–144 IU) per cup, where the product is fortified
• Egg yolks and liver: small amounts, well under 2 µg per serve
• Fortified margarines, milk powders and breakfast cereals: around 2 µg (80 IU) per serve; fortification in Australia is permitted rather than universal

This list is the part of the page we will not shorten. If any of it applies to you, talk to one of our naturopaths or your doctor before starting.

• Hypercalcaemia, hypercalciuria, or any condition causing them. Contraindicated.
• Hypervitaminosis D. Contraindicated.
• Nephrolithiasis (kidney stones) and severe renal impairment. Contraindicated outside medical direction.
• Hypersensitivity to any product ingredient. Contraindicated.
• Long-term daily doses above 1,000 IU. Serum calcium, urinary calcium and renal function should be monitored.
• Thiazide diuretics. Increased risk of hypercalcaemia.
• Digoxin and other cardiac glycosides. Effects may be accentuated with vitamin D plus calcium.
• Anticonvulsants and barbiturates. May reduce vitamin D effectiveness.
• Corticosteroids. Impair vitamin D metabolism and calcium absorption.
• Orlistat. Reduces absorption of fat-soluble vitamins.
• Statins. Bidirectional interaction reported via shared metabolic pathways.
• Malabsorption states: coeliac, Crohn's, cystic fibrosis, liver disease, bariatric surgery.
• Infants and children. Lower Upper Level and paediatric dosing; 25 µg/day is the Upper Level under 12 months.
• Pregnancy and breastfeeding. Dose to be set with a midwife or doctor.
• D3 with K2 products where warfarin or another vitamin K-sensitive anticoagulant is taken.
• Nausea, vomiting, constipation, thirst, polyuria, weakness, apathy or confusion. Possible hypercalcaemia; seek advice.
• If you take prescription medicines, check with your doctor, pharmacist or our naturopaths before starting.