Vitamin A and Vitamin C: study protocols
24 study groups took Vitamin A together with Vitamin C. These are the doses the studies gave. They are not a recommendation.
Dose per serving from research: Vitamin A
16 study groups in 11 studies say how much Vitamin A participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 250 mcg to 500 mcg and 500 mcg to 1 mg, 38% of 16 study groups each.
| Daily dose | Study groups |
|---|---|
| 100 mcg to 250 mcg | 2 |
| 250 mcg to 500 mcg | 6 |
| 500 mcg to 1 mg | 6 |
| 1 mg to 2.5 mg | 0 |
| 2.5 mg to 5 mg | 2 |
Dose per serving from research: Vitamin C
22 study groups in 16 studies say how much Vitamin C participants took a day.
These are the doses the studies gave. They are not a recommendation.
Most common: 25 mg to 50 mg, 36% of 22 study groups.
| Daily dose | Study groups |
|---|---|
| 5 mg or less | 1 |
| 5 mg to 10 mg | 2 |
| 10 mg to 25 mg | 1 |
| 25 mg to 50 mg | 8 |
| 50 mg to 100 mg | 4 |
| 100 mg to 250 mg | 0 |
| 250 mg to 500 mg | 5 |
| over 500 mg | 1 |
Commonly used together
23 of 24 study groups took Vitamin A and Vitamin C with something else. Shown: what 3 or more different studies gave. The 10 most common of 14.
What was given together, not what works together.
| Taken with | Study groups |
|---|---|
| Iron | 15 |
| Zinc | 14 |
| Folic Acid | 10 |
| Vitamin E | 10 |
| Copper | 7 |
| Selenium | 7 |
| Vitamin B12 | 7 |
| Vitamin B6 | 6 |
| Iodine | 5 |
| Vitamin D | 5 |
24 study groups
| Study | ||||
|---|---|---|---|---|
| Impact of iron fortification on anaemia and iron deficiency among pre-school children living in Rural Ghana 2021 · non-iron MNP group · Children aged 6–35 months living in rural Ghana; children with severe anaemia, severe malnutrition, recent iron supplementation, or chronic disease were excluded. | 400 mcg | 30 mg | 150 days | 991 |
| Antioxidant vitamins or lactulose for the prevention of the recurrence of colorectal adenomas. Colorectal Cancer Study Group of the University of Modena and the Health Care District 16 1993 · Group 1 (vitamins) · Individuals after endoscopic polypectomy; age and sex not reported; adenomas were the condition of interest. | 30,000 IU | 1 g | 548 days | — |
| Impact of iron fortification on anaemia and iron deficiency among pre-school children living in Rural Ghana 2021 · iron-MNP group · Children aged 6–35 months living in rural Ghana; children with severe anaemia, severe malnutrition, recent iron supplementation, or chronic disease were excluded. | 400 mcg | 30 mg | 150 days | 967 |
| Effects of maternal micronutrient supplementation on fetal loss and infant mortality: a cluster-randomized trial in Nepal 2003 · Multiple micronutrients · Pregnant women in rural Nepal | 1 mg | 100 mg | — | — |
| Multivitamin supplementation of HIV-positive women during pregnancy reduces hypertension 2005 · Multivitamin plus vitamin A · HIV-positive pregnant Tanzanian women | 5,000 IU | 500 mg | — | — |
| Effect of micronutrient supplementation on diarrhoeal disease among stunted children in rural South Africa 2009 · multiple micronutrients · children aged 6–24 months; three cohorts: HIV-infected children, HIV-uninfected children born to HIV-infected mothers, and HIV-uninfected children born to HIV-uninfected mothers | 1,250 IU | 35 mg | 548 days | — |
| Supplementation with multivitamins and vitamin A and incidence of malaria among HIV-infected Tanzanian women 2014 · multivitamins with vitamin A · HIV-infected pregnant women in Tanzania | 5,000 IU | 500 mg | 1249 days | — |
| Double-blind, randomized, controlled trial of zinc or vitamin A supplementation in young children with acute diarrhoea 1999 · vitamin A · Children aged 6 months to 2 years with acute watery diarrhoea of 3 days or less and some dehydration | 4.5 mg | — | 15 days | — |
| Double-blind, randomized, controlled trial of zinc or vitamin A supplementation in young children with acute diarrhoea 1999 · vitamin A plus zinc · Children aged 6 months to 2 years with acute watery diarrhoea of 3 days or less and some dehydration | 4.5 mg | — | 15 days | — |
| Micronutrient fortified milk improves iron status, anemia and growth among children 1-4 years: a double masked, randomized, controlled trial 2010 · Micronutrient-fortified milk (MN group) · Children aged 1–4 years in India; many had anemia, iron deficiency, or growth faltering | 156 mcg | 40.2 mg | 1 year | 316 |